annotate scripts/special-matrix/gallery.m @ 31551:fd29c7a50a78 stable

maint: use commas, semicolons consistently with Octave conventions. * makeValidName.m: Remove %!test and move BIST %!asserts to column 1. * base64decode.m, base64encode.m, which.m, logm.m, uniquetol.m, perms.m: Delete semicolon (';') at end of %!assert BIST. * lin2mu.m, interp2.m, interpn.m, lsqnonneg.m, pqpnonneg.m, uniquetol.m, betainc.m, normalize.m: Add semicolon (';') to end of assert statement within %!test BIST. * __memoize__.m, tar_is_bsd.m, publish.m: Add semicolon (';') to line with keyword "persistent". * stft.m: Use comma (',') after "case" keyword when code immediately follows. * gallery.m: Align commas used in case statements in massive switch block. Remove unnecessary parentheses around a numeric case argument. * ranks.m: Remove semicolon (';') from case statemnt argument.
author Rik <rik@octave.org>
date Sat, 26 Nov 2022 06:32:08 -0800
parents c8ad083a5802
children 597f3ee61a48
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
27923
bd51beb6205e update formatting of copyright notices
John W. Eaton <jwe@octave.org>
parents: 27919
diff changeset
1 ########################################################################
bd51beb6205e update formatting of copyright notices
John W. Eaton <jwe@octave.org>
parents: 27919
diff changeset
2 ##
30564
796f54d4ddbf update Octave Project Developers copyright for the new year
John W. Eaton <jwe@octave.org>
parents: 30379
diff changeset
3 ## Copyright (C) 1989-2022 The Octave Project Developers
27918
b442ec6dda5c use centralized file for copyright info for individual contributors
John W. Eaton <jwe@octave.org>
parents: 27216
diff changeset
4 ##
27923
bd51beb6205e update formatting of copyright notices
John W. Eaton <jwe@octave.org>
parents: 27919
diff changeset
5 ## See the file COPYRIGHT.md in the top-level directory of this
bd51beb6205e update formatting of copyright notices
John W. Eaton <jwe@octave.org>
parents: 27919
diff changeset
6 ## distribution or <https://octave.org/copyright/>.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
7 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
8 ## This file is part of Octave.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
9 ##
24534
194eb4bd202b maint: Update punctuation for GPL v3 license text.
Rik <rik@octave.org>
parents: 23384
diff changeset
10 ## Octave is free software: you can redistribute it and/or modify it
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
11 ## under the terms of the GNU General Public License as published by
24534
194eb4bd202b maint: Update punctuation for GPL v3 license text.
Rik <rik@octave.org>
parents: 23384
diff changeset
12 ## the Free Software Foundation, either version 3 of the License, or
22755
3a2b891d0b33 maint: Standardize Copyright formatting.
Rik <rik@octave.org>
parents: 22323
diff changeset
13 ## (at your option) any later version.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
14 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
15 ## Octave is distributed in the hope that it will be useful, but
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
16 ## WITHOUT ANY WARRANTY; without even the implied warranty of
22755
3a2b891d0b33 maint: Standardize Copyright formatting.
Rik <rik@octave.org>
parents: 22323
diff changeset
17 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
3a2b891d0b33 maint: Standardize Copyright formatting.
Rik <rik@octave.org>
parents: 22323
diff changeset
18 ## GNU General Public License for more details.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
19 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
20 ## You should have received a copy of the GNU General Public License
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
21 ## along with Octave; see the file COPYING. If not, see
24534
194eb4bd202b maint: Update punctuation for GPL v3 license text.
Rik <rik@octave.org>
parents: 23384
diff changeset
22 ## <https://www.gnu.org/licenses/>.
27923
bd51beb6205e update formatting of copyright notices
John W. Eaton <jwe@octave.org>
parents: 27919
diff changeset
23 ##
bd51beb6205e update formatting of copyright notices
John W. Eaton <jwe@octave.org>
parents: 27919
diff changeset
24 ########################################################################
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
25
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
26 ## -*- texinfo -*-
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
27 ## @deftypefn {} {} gallery (@var{name})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
28 ## @deftypefnx {} {} gallery (@var{name}, @var{args})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
29 ## Create interesting matrices for testing.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
30 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
31 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
32 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
33 ## @deftypefn {} {@var{c} =} gallery ("cauchy", @var{x})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
34 ## @deftypefnx {} {@var{c} =} gallery ("cauchy", @var{x}, @var{y})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
35 ## Create a Cauchy matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
36 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
37 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
38 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
39 ## @deftypefn {} {@var{c} =} gallery ("chebspec", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
40 ## @deftypefnx {} {@var{c} =} gallery ("chebspec", @var{n}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
41 ## Create a Chebyshev spectral differentiation matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
42 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
43 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
44 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
45 ## @deftypefn {} {@var{c} =} gallery ("chebvand", @var{p})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
46 ## @deftypefnx {} {@var{c} =} gallery ("chebvand", @var{m}, @var{p})
25003
2365c2661b3c doc: Spellcheck documentation ahead of 4.4 release.
Rik <rik@octave.org>
parents: 24534
diff changeset
47 ## Create a @nospell{Vandermonde}-like matrix for the Chebyshev polynomials.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
48 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
49 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
50 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
51 ## @deftypefn {} {@var{a} =} gallery ("chow", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
52 ## @deftypefnx {} {@var{a} =} gallery ("chow", @var{n}, @var{alpha})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
53 ## @deftypefnx {} {@var{a} =} gallery ("chow", @var{n}, @var{alpha}, @var{delta})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
54 ## Create a Chow matrix -- a singular Toeplitz lower Hessenberg matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
55 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
56 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
57 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
58 ## @deftypefn {} {@var{c} =} gallery ("circul", @var{v})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
59 ## Create a circulant matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
60 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
61 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
62 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
63 ## @deftypefn {} {@var{a} =} gallery ("clement", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
64 ## @deftypefnx {} {@var{a} =} gallery ("clement", @var{n}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
65 ## Create a tridiagonal matrix with zero diagonal entries.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
66 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
67 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
68 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
69 ## @deftypefn {} {@var{c} =} gallery ("compar", @var{a})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
70 ## @deftypefnx {} {@var{c} =} gallery ("compar", @var{a}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
71 ## Create a comparison matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
72 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
73 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
74 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
75 ## @deftypefn {} {@var{a} =} gallery ("condex", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
76 ## @deftypefnx {} {@var{a} =} gallery ("condex", @var{n}, @var{k})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
77 ## @deftypefnx {} {@var{a} =} gallery ("condex", @var{n}, @var{k}, @var{theta})
27931
0fa21907e54c doc: grammarcheck documentation ahead of 6.1 release.
Rik <rik@octave.org>
parents: 27923
diff changeset
78 ## Create a @nospell{"counterexample"} matrix to a condition estimator.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
79 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
80 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
81 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
82 ## @deftypefn {} {@var{a} =} gallery ("cycol", [@var{m} @var{n}])
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
83 ## @deftypefnx {} {@var{a} =} gallery ("cycol", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
84 ## @deftypefnx {} {@var{a} =} gallery (@dots{}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
85 ## Create a matrix whose columns repeat cyclically.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
86 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
87 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
88 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
89 ## @deftypefn {} {[@var{c}, @var{d}, @var{e}] =} gallery ("dorr", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
90 ## @deftypefnx {} {[@var{c}, @var{d}, @var{e}] =} gallery ("dorr", @var{n}, @var{theta})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
91 ## @deftypefnx {} {@var{a} =} gallery ("dorr", @dots{})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
92 ## Create a diagonally dominant, ill-conditioned, tridiagonal matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
93 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
94 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
95 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
96 ## @deftypefn {} {@var{a} =} gallery ("dramadah", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
97 ## @deftypefnx {} {@var{a} =} gallery ("dramadah", @var{n}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
98 ## Create a (0, 1) matrix whose inverse has large integer entries.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
99 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
100 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
101 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
102 ## @deftypefn {} {@var{a} =} gallery ("fiedler", @var{c})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
103 ## Create a symmetric @nospell{Fiedler} matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
104 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
105 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
106 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
107 ## @deftypefn {} {@var{a} =} gallery ("forsythe", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
108 ## @deftypefnx {} {@var{a} =} gallery ("forsythe", @var{n}, @var{alpha})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
109 ## @deftypefnx {} {@var{a} =} gallery ("forsythe", @var{n}, @var{alpha}, @var{lambda})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
110 ## Create a @nospell{Forsythe} matrix (a perturbed Jordan block).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
111 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
112 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
113 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
114 ## @deftypefn {} {@var{f} =} gallery ("frank", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
115 ## @deftypefnx {} {@var{f} =} gallery ("frank", @var{n}, @var{k})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
116 ## Create a Frank matrix (ill-conditioned eigenvalues).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
117 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
118 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
119 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
120 ## @deftypefn {} {@var{c} =} gallery ("gcdmat", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
121 ## Create a greatest common divisor matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
122 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
123 ## @var{c} is an @var{n}-by-@var{n} matrix whose values correspond to the
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
124 ## greatest common divisor of its coordinate values, i.e., @var{c}(i,j)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
125 ## correspond @code{gcd (i, j)}.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
126 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
127 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
128 ## @deftypefn {} {@var{a} =} gallery ("gearmat", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
129 ## @deftypefnx {} {@var{a} =} gallery ("gearmat", @var{n}, @var{i})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
130 ## @deftypefnx {} {@var{a} =} gallery ("gearmat", @var{n}, @var{i}, @var{j})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
131 ## Create a Gear matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
132 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
133 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
134 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
135 ## @deftypefn {} {@var{g} =} gallery ("grcar", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
136 ## @deftypefnx {} {@var{g} =} gallery ("grcar", @var{n}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
137 ## Create a Toeplitz matrix with sensitive eigenvalues.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
138 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
139 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
140 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
141 ## @deftypefn {} {@var{a} =} gallery ("hanowa", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
142 ## @deftypefnx {} {@var{a} =} gallery ("hanowa", @var{n}, @var{d})
16816
12005245b645 doc: Periodic grammarcheck of documentation.
Rik <rik@octave.org>
parents: 16766
diff changeset
143 ## Create a matrix whose eigenvalues lie on a vertical line in the complex
12005245b645 doc: Periodic grammarcheck of documentation.
Rik <rik@octave.org>
parents: 16766
diff changeset
144 ## plane.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
145 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
146 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
147 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
148 ## @deftypefn {} {@var{v} =} gallery ("house", @var{x})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
149 ## @deftypefnx {} {[@var{v}, @var{beta}] =} gallery ("house", @var{x})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
150 ## Create a householder matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
151 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
152 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
153 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
154 ## @deftypefn {} {@var{a} =} gallery ("integerdata", @var{imax}, [@var{M} @var{N} @dots{}], @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
155 ## @deftypefnx {} {@var{a} =} gallery ("integerdata", @var{imax}, @var{M}, @var{N}, @dots{}, @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
156 ## @deftypefnx {} {@var{a} =} gallery ("integerdata", [@var{imin}, @var{imax}], [@var{M} @var{N} @dots{}], @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
157 ## @deftypefnx {} {@var{a} =} gallery ("integerdata", [@var{imin}, @var{imax}], @var{M}, @var{N}, @dots{}, @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
158 ## @deftypefnx {} {@var{a} =} gallery ("integerdata", @dots{}, "@var{class}")
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
159 ## Create a matrix with random integers in the range [1, @var{imax}].
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
160 ## If @var{imin} is given then the integers are in the range
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
161 ## [@var{imin}, @var{imax}].
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
162 ##
21546
f7f97d7e9294 doc: Wrap m-file docstrings to 79 characters + newline (80 total).
Rik <rik@octave.org>
parents: 21385
diff changeset
163 ## The second input is a matrix of dimensions describing the size of the
f7f97d7e9294 doc: Wrap m-file docstrings to 79 characters + newline (80 total).
Rik <rik@octave.org>
parents: 21385
diff changeset
164 ## output. The dimensions can also be input as comma-separated arguments.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
165 ##
20162
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
166 ## The input @var{j} is an integer index in the range [0, 2^32-1]. The values
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
167 ## of the output matrix are always exactly the same (reproducibility) for a
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
168 ## given size input and @var{j} index.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
169 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
170 ## The final optional argument determines the class of the resulting matrix.
17281
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
171 ## Possible values for @var{class}: @qcode{"uint8"}, @qcode{"uint16"},
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
172 ## @qcode{"uint32"}, @qcode{"int8"}, @qcode{"int16"}, int32", @qcode{"single"},
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
173 ## @qcode{"double"}. The default is @qcode{"double"}.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
174 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
175 ## @end deftypefn
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
176 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
177 ## @deftypefn {} {@var{a} =} gallery ("invhess", @var{x})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
178 ## @deftypefnx {} {@var{a} =} gallery ("invhess", @var{x}, @var{y})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
179 ## Create the inverse of an upper Hessenberg matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
180 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
181 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
182 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
183 ## @deftypefn {} {@var{a} =} gallery ("invol", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
184 ## Create an involutory matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
185 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
186 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
187 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
188 ## @deftypefn {} {@var{a} =} gallery ("ipjfact", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
189 ## @deftypefnx {} {@var{a} =} gallery ("ipjfact", @var{n}, @var{k})
20162
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
190 ## Create a Hankel matrix with factorial elements.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
191 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
192 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
193 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
194 ## @deftypefn {} {@var{a} =} gallery ("jordbloc", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
195 ## @deftypefnx {} {@var{a} =} gallery ("jordbloc", @var{n}, @var{lambda})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
196 ## Create a Jordan block.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
197 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
198 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
199 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
200 ## @deftypefn {} {@var{u} =} gallery ("kahan", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
201 ## @deftypefnx {} {@var{u} =} gallery ("kahan", @var{n}, @var{theta})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
202 ## @deftypefnx {} {@var{u} =} gallery ("kahan", @var{n}, @var{theta}, @var{pert})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
203 ## Create a @nospell{Kahan} matrix (upper trapezoidal).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
204 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
205 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
206 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
207 ## @deftypefn {} {@var{a} =} gallery ("kms", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
208 ## @deftypefnx {} {@var{a} =} gallery ("kms", @var{n}, @var{rho})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
209 ## Create a @nospell{Kac-Murdock-Szego} Toeplitz matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
210 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
211 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
212 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
213 ## @deftypefn {} {@var{b} =} gallery ("krylov", @var{a})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
214 ## @deftypefnx {} {@var{b} =} gallery ("krylov", @var{a}, @var{x})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
215 ## @deftypefnx {} {@var{b} =} gallery ("krylov", @var{a}, @var{x}, @var{j})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
216 ## Create a Krylov matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
217 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
218 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
219 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
220 ## @deftypefn {} {@var{a} =} gallery ("lauchli", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
221 ## @deftypefnx {} {@var{a} =} gallery ("lauchli", @var{n}, @var{mu})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
222 ## Create a @nospell{Lauchli} matrix (rectangular).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
223 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
224 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
225 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
226 ## @deftypefn {} {@var{a} =} gallery ("lehmer", @var{n})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
227 ## Create a @nospell{Lehmer} matrix (symmetric positive definite).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
228 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
229 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
230 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
231 ## @deftypefn {} {@var{t} =} gallery ("lesp", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
232 ## Create a tridiagonal matrix with real, sensitive eigenvalues.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
233 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
234 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
235 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
236 ## @deftypefn {} {@var{a} =} gallery ("lotkin", @var{n})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
237 ## Create a @nospell{Lotkin} matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
238 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
239 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
240 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
241 ## @deftypefn {} {@var{a} =} gallery ("minij", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
242 ## Create a symmetric positive definite matrix MIN(i,j).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
243 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
244 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
245 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
246 ## @deftypefn {} {@var{a} =} gallery ("moler", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
247 ## @deftypefnx {} {@var{a} =} gallery ("moler", @var{n}, @var{alpha})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
248 ## Create a @nospell{Moler} matrix (symmetric positive definite).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
249 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
250 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
251 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
252 ## @deftypefn {} {[@var{a}, @var{t}] =} gallery ("neumann", @var{n})
25003
2365c2661b3c doc: Spellcheck documentation ahead of 4.4 release.
Rik <rik@octave.org>
parents: 24534
diff changeset
253 ## Create a singular matrix from the discrete @nospell{Neumann} problem
2365c2661b3c doc: Spellcheck documentation ahead of 4.4 release.
Rik <rik@octave.org>
parents: 24534
diff changeset
254 ## (sparse).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
255 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
256 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
257 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
258 ## @deftypefn {} {@var{a} =} gallery ("normaldata", [@var{M} @var{N} @dots{}], @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
259 ## @deftypefnx {} {@var{a} =} gallery ("normaldata", @var{M}, @var{N}, @dots{}, @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
260 ## @deftypefnx {} {@var{a} =} gallery ("normaldata", @dots{}, "@var{class}")
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
261 ## Create a matrix with random samples from the standard normal distribution
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
262 ## (mean = 0, std = 1).
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
263 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
264 ## The first input is a matrix of dimensions describing the size of the output.
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
265 ## The dimensions can also be input as comma-separated arguments.
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
266 ##
20162
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
267 ## The input @var{j} is an integer index in the range [0, 2^32-1]. The values
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
268 ## of the output matrix are always exactly the same (reproducibility) for a
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
269 ## given size input and @var{j} index.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
270 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
271 ## The final optional argument determines the class of the resulting matrix.
17281
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
272 ## Possible values for @var{class}: @qcode{"single"}, @qcode{"double"}.
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
273 ## The default is @qcode{"double"}.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
274 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
275 ## @end deftypefn
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
276 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
277 ## @deftypefn {} {@var{q} =} gallery ("orthog", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
278 ## @deftypefnx {} {@var{q} =} gallery ("orthog", @var{n}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
279 ## Create orthogonal and nearly orthogonal matrices.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
280 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
281 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
282 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
283 ## @deftypefn {} {@var{a} =} gallery ("parter", @var{n})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
284 ## Create a @nospell{Parter} matrix (a Toeplitz matrix with singular values
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
285 ## near pi).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
286 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
287 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
288 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
289 ## @deftypefn {} {@var{p} =} gallery ("pei", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
290 ## @deftypefnx {} {@var{p} =} gallery ("pei", @var{n}, @var{alpha})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
291 ## Create a Pei matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
292 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
293 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
294 ##
27085
47b81207cb32 gallery.m: Fix typo in docstring for poisson (bug #56267).
Rik <rik@octave.org>
parents: 26376
diff changeset
295 ## @deftypefn {} {@var{a} =} gallery ("poisson", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
296 ## Create a block tridiagonal matrix from Poisson's equation (sparse).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
297 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
298 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
299 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
300 ## @deftypefn {} {@var{a} =} gallery ("prolate", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
301 ## @deftypefnx {} {@var{a} =} gallery ("prolate", @var{n}, @var{w})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
302 ## Create a prolate matrix (symmetric, ill-conditioned Toeplitz matrix).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
303 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
304 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
305 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
306 ## @deftypefn {} {@var{h} =} gallery ("randhess", @var{x})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
307 ## Create a random, orthogonal upper Hessenberg matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
308 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
309 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
310 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
311 ## @deftypefn {} {@var{a} =} gallery ("rando", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
312 ## @deftypefnx {} {@var{a} =} gallery ("rando", @var{n}, @var{k})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
313 ## Create a random matrix with elements -1, 0 or 1.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
314 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
315 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
316 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
317 ## @deftypefn {} {@var{a} =} gallery ("randsvd", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
318 ## @deftypefnx {} {@var{a} =} gallery ("randsvd", @var{n}, @var{kappa})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
319 ## @deftypefnx {} {@var{a} =} gallery ("randsvd", @var{n}, @var{kappa}, @var{mode})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
320 ## @deftypefnx {} {@var{a} =} gallery ("randsvd", @var{n}, @var{kappa}, @var{mode}, @var{kl})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
321 ## @deftypefnx {} {@var{a} =} gallery ("randsvd", @var{n}, @var{kappa}, @var{mode}, @var{kl}, @var{ku})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
322 ## Create a random matrix with pre-assigned singular values.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
323 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
324 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
325 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
326 ## @deftypefn {} {@var{a} =} gallery ("redheff", @var{n})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
327 ## Create a zero and ones matrix of @nospell{Redheffer} associated with the
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
328 ## Riemann hypothesis.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
329 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
330 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
331 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
332 ## @deftypefn {} {@var{a} =} gallery ("riemann", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
333 ## Create a matrix associated with the Riemann hypothesis.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
334 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
335 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
336 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
337 ## @deftypefn {} {@var{a} =} gallery ("ris", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
338 ## Create a symmetric Hankel matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
339 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
340 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
341 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
342 ## @deftypefn {} {@var{a} =} gallery ("smoke", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
343 ## @deftypefnx {} {@var{a} =} gallery ("smoke", @var{n}, @var{k})
27931
0fa21907e54c doc: grammarcheck documentation ahead of 6.1 release.
Rik <rik@octave.org>
parents: 27923
diff changeset
344 ## Create a complex matrix, with a @nospell{"smoke ring"} pseudospectrum.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
345 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
346 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
347 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
348 ## @deftypefn {} {@var{t} =} gallery ("toeppd", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
349 ## @deftypefnx {} {@var{t} =} gallery ("toeppd", @var{n}, @var{m})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
350 ## @deftypefnx {} {@var{t} =} gallery ("toeppd", @var{n}, @var{m}, @var{w})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
351 ## @deftypefnx {} {@var{t} =} gallery ("toeppd", @var{n}, @var{m}, @var{w}, @var{theta})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
352 ## Create a symmetric positive definite Toeplitz matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
353 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
354 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
355 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
356 ## @deftypefn {} {@var{p} =} gallery ("toeppen", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
357 ## @deftypefnx {} {@var{p} =} gallery ("toeppen", @var{n}, @var{a})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
358 ## @deftypefnx {} {@var{p} =} gallery ("toeppen", @var{n}, @var{a}, @var{b})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
359 ## @deftypefnx {} {@var{p} =} gallery ("toeppen", @var{n}, @var{a}, @var{b}, @var{c})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
360 ## @deftypefnx {} {@var{p} =} gallery ("toeppen", @var{n}, @var{a}, @var{b}, @var{c}, @var{d})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
361 ## @deftypefnx {} {@var{p} =} gallery ("toeppen", @var{n}, @var{a}, @var{b}, @var{c}, @var{d}, @var{e})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
362 ## Create a pentadiagonal Toeplitz matrix (sparse).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
363 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
364 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
365 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
366 ## @deftypefn {} {@var{a} =} gallery ("tridiag", @var{x}, @var{y}, @var{z})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
367 ## @deftypefnx {} {@var{a} =} gallery ("tridiag", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
368 ## @deftypefnx {} {@var{a} =} gallery ("tridiag", @var{n}, @var{c}, @var{d}, @var{e})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
369 ## Create a tridiagonal matrix (sparse).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
370 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
371 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
372 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
373 ## @deftypefn {} {@var{t} =} gallery ("triw", @var{n})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
374 ## @deftypefnx {} {@var{t} =} gallery ("triw", @var{n}, @var{alpha})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
375 ## @deftypefnx {} {@var{t} =} gallery ("triw", @var{n}, @var{alpha}, @var{k})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
376 ## Create an upper triangular matrix discussed by
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
377 ## @nospell{Kahan, Golub, and Wilkinson}.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
378 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
379 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
380 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
381 ## @deftypefn {} {@var{a} =} gallery ("uniformdata", [@var{M} @var{N} @dots{}], @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
382 ## @deftypefnx {} {@var{a} =} gallery ("uniformdata", @var{M}, @var{N}, @dots{}, @var{j})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
383 ## @deftypefnx {} {@var{a} =} gallery ("uniformdata", @dots{}, "@var{class}")
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
384 ## Create a matrix with random samples from the standard uniform distribution
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
385 ## (range [0,1]).
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
386 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
387 ## The first input is a matrix of dimensions describing the size of the output.
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
388 ## The dimensions can also be input as comma-separated arguments.
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
389 ##
20162
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
390 ## The input @var{j} is an integer index in the range [0, 2^32-1]. The values
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
391 ## of the output matrix are always exactly the same (reproducibility) for a
2645f9ef8c88 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19944
diff changeset
392 ## given size input and @var{j} index.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
393 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
394 ## The final optional argument determines the class of the resulting matrix.
17281
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
395 ## Possible values for @var{class}: @qcode{"single"}, @qcode{"double"}.
bc924baa2c4e doc: Add new @qcode macro for code samples which are quoted.
Rik <rik@octave.org>
parents: 17199
diff changeset
396 ## The default is @qcode{"double"}.
16982
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
397 ##
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
398 ## @end deftypefn
badc46a0a230 doc: Document 'uniformdata', 'normaldata', 'integerdata' matrices in gallery.m.
Rik <rik@octave.org>
parents: 16980
diff changeset
399 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
400 ## @deftypefn {} {@var{a} =} gallery ("wathen", @var{nx}, @var{ny})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
401 ## @deftypefnx {} {@var{a} =} gallery ("wathen", @var{nx}, @var{ny}, @var{k})
19040
0850b5212619 doc: Add @nospell macro around proper names in documentation.
Rik <rik@octave.org>
parents: 18846
diff changeset
402 ## Create the @nospell{Wathen} matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
403 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
404 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
405 ##
20852
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20299
diff changeset
406 ## @deftypefn {} {[@var{a}, @var{b}] =} gallery ("wilk", @var{n})
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
407 ## Create various specific matrices devised/discussed by Wilkinson.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
408 ##
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
409 ## @end deftypefn
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
410
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
411 ## Code for most of the individual matrices (except binomial, gcdmat,
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
412 ## integerdata, leslie, normaldata, randcolu, randcorr, randjorth, sampling,
21751
b571fc85953f maint: Use two spaces after period to indicate sentence break.
Rik <rik@octave.org>
parents: 21562
diff changeset
413 ## uniformdata) by Nicholas J. Higham <Nicholas.J.Higham@manchester.ac.uk>
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
414 ## Adapted for Octave and into single gallery function by Carnë Draug
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
415
28904
930cb0ae24fd maint: Don't enclose single output of function with '[]'.
Rik <rik@octave.org>
parents: 28896
diff changeset
416 function varargout = gallery (name, varargin)
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
417
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
418 if (nargin < 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
419 print_usage ();
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
420 elseif (! ischar (name))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
421 error ("gallery: NAME must be a string");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
422 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
423
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
424 ## NOTE: there isn't a lot of input check in the individual functions
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
425 ## that actually build the functions. This is by design. The original
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
426 ## code by Higham did not perform it and was propagated to Matlab, so
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
427 ## for compatibility, we also don't make it. For example, arguments
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
428 ## that behave as switches, and in theory accepting a value of 0 or 1,
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
429 ## will use a value of 0, for any value other than 1 (only check made
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
430 ## is if the value is equal to 1). It will often also accept string
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
431 ## values instead of numeric. Only input check added was where it
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
432 ## would be causing an error anyway.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
433
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
434 ## we will always want to return at least 1 output
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
435 n_out = nargout;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
436 if (n_out == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
437 n_out = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
438 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
439
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
440 switch (tolower (name))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
441 case "binomial"
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
442 error ("gallery: matrix %s not implemented", name);
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
443 case "cauchy" , [varargout{1:n_out}] = cauchy (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
444 case "chebspec" , [varargout{1:n_out}] = chebspec (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
445 case "chebvand" , [varargout{1:n_out}] = chebvand (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
446 case "chow" , [varargout{1:n_out}] = chow (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
447 case "circul" , [varargout{1:n_out}] = circul (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
448 case "clement" , [varargout{1:n_out}] = clement (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
449 case "compar" , [varargout{1:n_out}] = compar (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
450 case "condex" , [varargout{1:n_out}] = condex (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
451 case "cycol" , [varargout{1:n_out}] = cycol (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
452 case "dorr" , [varargout{1:n_out}] = dorr (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
453 case "dramadah" , [varargout{1:n_out}] = dramadah (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
454 case "fiedler" , [varargout{1:n_out}] = fiedler (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
455 case "forsythe" , [varargout{1:n_out}] = forsythe (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
456 case "frank" , [varargout{1:n_out}] = frank (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
457 case "gearmat" , [varargout{1:n_out}] = gearmat (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
458 case "gcdmat" , [varargout{1:n_out}] = gcdmat (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
459 case "grcar" , [varargout{1:n_out}] = grcar (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
460 case "hanowa" , [varargout{1:n_out}] = hanowa (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
461 case "house" , [varargout{1:n_out}] = house (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
462 case "integerdata" , [varargout{1:n_out}] = integerdata (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
463 case "invhess" , [varargout{1:n_out}] = invhess (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
464 case "invol" , [varargout{1:n_out}] = invol (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
465 case "ipjfact" , [varargout{1:n_out}] = ipjfact (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
466 case "jordbloc" , [varargout{1:n_out}] = jordbloc (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
467 case "kahan" , [varargout{1:n_out}] = kahan (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
468 case "kms" , [varargout{1:n_out}] = kms (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
469 case "krylov" , [varargout{1:n_out}] = krylov (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
470 case "lauchli" , [varargout{1:n_out}] = lauchli (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
471 case "lehmer" , [varargout{1:n_out}] = lehmer (varargin{:});
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
472 case "leslie"
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
473 error ("gallery: matrix %s not implemented", name);
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
474 case "lesp" , [varargout{1:n_out}] = lesp (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
475 case "lotkin" , [varargout{1:n_out}] = lotkin (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
476 case "minij" , [varargout{1:n_out}] = minij (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
477 case "moler" , [varargout{1:n_out}] = moler (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
478 case "neumann" , [varargout{1:n_out}] = neumann (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
479 case "normaldata" , [varargout{1:n_out}] = normaldata (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
480 case "orthog" , [varargout{1:n_out}] = orthog (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
481 case "parter" , [varargout{1:n_out}] = parter (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
482 case "pei" , [varargout{1:n_out}] = pei (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
483 case "poisson" , [varargout{1:n_out}] = poisson (varargin{:});
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
484 case "prolate" , [varargout{1:n_out}] = prolate (varargin{:});
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
485 case "randcolu"
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
486 error ("gallery: matrix %s not implemented", name);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
487 case "randcorr"
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
488 error ("gallery: matrix %s not implemented", name);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
489 case "randhess" , [varargout{1:n_out}] = randhess (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
490 case "randjorth"
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
491 error ("gallery: matrix %s not implemented", name);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
492 case "rando" , [varargout{1:n_out}] = rando (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
493 case "randsvd" , [varargout{1:n_out}] = randsvd (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
494 case "redheff" , [varargout{1:n_out}] = redheff (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
495 case "riemann" , [varargout{1:n_out}] = riemann (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
496 case "ris" , [varargout{1:n_out}] = ris (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
497 case "sampling"
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
498 error ("gallery: matrix %s not implemented", name);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
499 case "smoke" , [varargout{1:n_out}] = smoke (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
500 case "toeppd" , [varargout{1:n_out}] = toeppd (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
501 case "toeppen" , [varargout{1:n_out}] = toeppen (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
502 case "tridiag" , [varargout{1:n_out}] = tridiag (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
503 case "triw" , [varargout{1:n_out}] = triw (varargin{:});
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
504 case "uniformdata" , [varargout{1:n_out}] = uniformdata (varargin{:});
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
505 case "wathen" , [varargout{1:n_out}] = wathen (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
506 case "wilk" , [varargout{1:n_out}] = wilk (varargin{:});
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
507 otherwise
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
508 error ("gallery: unknown matrix with NAME %s", name);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
509 endswitch
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
510
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
511 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
512
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
513 function C = cauchy (x, y)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
514
21562
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
515 ## CAUCHY Cauchy matrix.
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
516 ## C = CAUCHY(X, Y), where X, Y are N-vectors, is the N-by-N matrix
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
517 ## with C(i,j) = 1/(X(i)+Y(j)). By default, Y = X.
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
518 ## Special case: if X is a scalar CAUCHY(X) is the same as CAUCHY(1:X).
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
519 ## Explicit formulas are known for DET(C) (which is nonzero if X and Y
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
520 ## both have distinct elements) and the elements of INV(C).
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
521 ## C is totally positive if 0 < X(1) < ... < X(N) and
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
522 ## 0 < Y(1) < ... < Y(N).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
523 ##
21562
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
524 ## References:
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
525 ## N.J. Higham, Accuracy and Stability of Numerical Algorithms,
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
526 ## Society for Industrial and Applied Mathematics, Philadelphia, PA,
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
527 ## USA, 1996; sec. 26.1.
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
528 ## D.E. Knuth, The Art of Computer Programming, Volume 1,
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
529 ## Fundamental Algorithms, second edition, Addison-Wesley, Reading,
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
530 ## Massachusetts, 1973, p. 36.
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
531 ## E.E. Tyrtyshnikov, Cauchy-Toeplitz matrices and some applications,
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
532 ## Linear Algebra and Appl., 149 (1991), pp. 1-18.
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
533 ## O. Taussky and M. Marcus, Eigenvalues of finite matrices, in
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
534 ## Survey of Numerical Analysis, J. Todd, ed., McGraw-Hill, New York,
6c2fd62db1f7 maint: Eliminate accidental double spaces in code.
Rik <rik@octave.org>
parents: 21546
diff changeset
535 ## pp. 279-313, 1962. (States the totally positive property on p. 295.)
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
536
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
537 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
538 error ("gallery: 1 or 2 arguments are required for cauchy matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
539 elseif (! isnumeric (x))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
540 error ("gallery: X must be numeric for cauchy matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
541 elseif (nargin == 2 && ! isnumeric (y))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
542 error ("gallery: Y must be numeric for cauchy matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
543 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
544
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
545 n = numel (x);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
546 if (isscalar (x) && fix (x) == x)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
547 n = x;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
548 x = 1:n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
549 elseif (n > 1 && isvector (x))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
550 ## do nothing
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
551 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
552 error ("gallery: X be an integer or a vector for cauchy matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
553 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
554
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
555 if (nargin == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
556 y = x;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
557 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
558
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
559 ## Ensure x and y are column vectors
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
560 x = x(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
561 y = y(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
562 if (numel (x) != numel (y))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
563 error ("gallery: X and Y must be vectors of same length for cauchy matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
564 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
565
30326
cd7c824f3f22 eliminate use of .+ and .- operators in Octave sources
John W. Eaton <jwe@octave.org>
parents: 29359
diff changeset
566 C = 1 ./ (x + y.');
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
567
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
568 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
569
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
570 function C = chebspec (n, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
571
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
572 ## CHEBSPEC Chebyshev spectral differentiation matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
573 ## C = CHEBSPEC(N, K) is a Chebyshev spectral differentiation
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
574 ## matrix of order N. K = 0 (the default) or 1.
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
575 ## For K = 0 ('no boundary conditions'), C is nilpotent, with
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
576 ## C^N = 0 and it has the null vector ONES(N,1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
577 ## C is similar to a Jordan block of size N with eigenvalue zero.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
578 ## For K = 1, C is nonsingular and well-conditioned, and its eigenvalues
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
579 ## have negative real parts.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
580 ## For both K, the computed eigenvector matrix X from EIG is
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
581 ## ill-conditioned (MESH(REAL(X)) is interesting).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
582 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
583 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
584 ## C. Canuto, M.Y. Hussaini, A. Quarteroni and T.A. Zang, Spectral
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
585 ## Methods in Fluid Dynamics, Springer-Verlag, Berlin, 1988; p. 69.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
586 ## L.N. Trefethen and M.R. Trummer, An instability phenomenon in
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
587 ## spectral methods, SIAM J. Numer. Anal., 24 (1987), pp. 1008-1023.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
588 ## D. Funaro, Computing the inverse of the Chebyshev collocation
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
589 ## derivative, SIAM J. Sci. Stat. Comput., 9 (1988), pp. 1050-1057.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
590
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
591 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
592 error ("gallery: 1 to 2 arguments are required for chebspec matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
593 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
594 error ("gallery: N must be an integer for chebspec matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
595 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
596 error ("gallery: K must be a scalar for chebspec matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
597 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
598
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
599 ## k = 1 case obtained from k = 0 case with one bigger n.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
600 switch (k)
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
601 case 0, # do nothing
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
602 case 1, n = n + 1;
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
603 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
604 error ("gallery: K should be either 0 or 1 for chebspec matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
605 endswitch
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
606
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
607 n -= 1;
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
608 C = zeros (n+1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
609
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
610 one = ones (n+1, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
611 x = cos ((0:n)' * (pi/n));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
612 d = ones (n+1, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
613 d(1) = 2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
614 d(n+1) = 2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
615
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
616 ## eye(size(C)) on next line avoids div by zero.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
617 C = (d * (one./d)') ./ (x*one'-one*x' + eye (size (C)));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
618
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
619 ## Now fix diagonal and signs.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
620 C(1,1) = (2*n^2+1)/6;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
621 for i = 2:n+1
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
622 if (rem (i, 2) == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
623 C(:,i) = -C(:,i);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
624 C(i,:) = -C(i,:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
625 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
626 if (i < n+1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
627 C(i,i) = -x(i)/(2*(1-x(i)^2));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
628 else
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
629 C(n+1,n+1) = -C(1,1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
630 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
631 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
632
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
633 if (k == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
634 C = C(2:n+1,2:n+1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
635 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
636
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
637 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
638
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
639 function C = chebvand (m, p)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
640
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
641 ## CHEBVAND Vandermonde-like matrix for the Chebyshev polynomials.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
642 ## C = CHEBVAND(P), where P is a vector, produces the (primal)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
643 ## Chebyshev Vandermonde matrix based on the points P,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
644 ## i.e., C(i,j) = T_{i-1}(P(j)), where T_{i-1} is the Chebyshev
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
645 ## polynomial of degree i-1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
646 ## CHEBVAND(M,P) is a rectangular version of CHEBVAND(P) with M rows.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
647 ## Special case: If P is a scalar then P equally spaced points on
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
648 ## [0,1] are used.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
649 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
650 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
651 ## N.J. Higham, Stability analysis of algorithms for solving confluent
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
652 ## Vandermonde-like systems, SIAM J. Matrix Anal. Appl., 11 (1990),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
653 ## pp. 23-41.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
654
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
655 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
656 error ("gallery: 1 or 2 arguments are required for chebvand matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
657 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
658
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
659 ## because the order of the arguments changes if nargin is 1 or 2 ...
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
660
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
661 if (nargin == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
662 p = m;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
663 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
664
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
665 n = numel (p);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
666 if (! isnumeric (p))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
667 error ("gallery: P must be numeric for chebvand matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
668 elseif (isscalar (p) && fix (p) == p)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
669 n = p;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
670 p = linspace (0, 1, n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
671 elseif (n > 1 && isvector (p))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
672 ## do nothing
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
673 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
674 p = p(:).'; # Ensure p is a row vector.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
675
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
676 if (nargin == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
677 m = n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
678 elseif (! isnumeric (m) || ! isscalar (m))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
679 error ("gallery: M must be a scalar for chebvand matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
680 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
681
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
682 C = ones (m, n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
683 if (m != 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
684 C(2,:) = p;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
685 ## Use Chebyshev polynomial recurrence.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
686 for i = 3:m
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
687 C(i,:) = 2.*p.*C(i-1,:) - C(i-2,:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
688 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
689 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
690
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
691 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
692
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
693 function A = chow (n, alpha = 1, delta = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
694
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
695 ## CHOW Chow matrix - a singular Toeplitz lower Hessenberg matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
696 ## A = CHOW(N, ALPHA, DELTA) is a Toeplitz lower Hessenberg matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
697 ## A = H(ALPHA) + DELTA*EYE, where H(i,j) = ALPHA^(i-j+1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
698 ## H(ALPHA) has p = FLOOR(N/2) zero eigenvalues, the rest being
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
699 ## 4*ALPHA*COS( k*PI/(N+2) )^2, k=1:N-p.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
700 ## Defaults: ALPHA = 1, DELTA = 0.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
701 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
702 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
703 ## T.S. Chow, A class of Hessenberg matrices with known
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
704 ## eigenvalues and inverses, SIAM Review, 11 (1969), pp. 391-395.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
705 ## G. Fairweather, On the eigenvalues and eigenvectors of a class of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
706 ## Hessenberg matrices, SIAM Review, 13 (1971), pp. 220-221.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
707
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
708 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
709 error ("gallery: 1 to 3 arguments are required for chow matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
710 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
711 error ("gallery: N must be an integer for chow matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
712 elseif (! isnumeric (alpha) || ! isscalar (alpha))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
713 error ("gallery: ALPHA must be a scalar for chow matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
714 elseif (! isnumeric (delta) || ! isscalar (delta))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
715 error ("gallery: DELTA must be a scalar for chow matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
716 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
717
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
718 A = toeplitz (alpha.^(1:n), [alpha 1 zeros(1, n-2)]) + delta * eye (n);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
719
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
720 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
721
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
722 function C = circul (v)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
723
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
724 ## CIRCUL Circulant matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
725 ## C = CIRCUL(V) is the circulant matrix whose first row is V.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
726 ## (A circulant matrix has the property that each row is obtained
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
727 ## from the previous one by cyclically permuting the entries one step
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
728 ## forward; it is a special Toeplitz matrix in which the diagonals
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
729 ## 'wrap round'.)
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
730 ## Special case: if V is a scalar then C = CIRCUL(1:V).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
731 ## The eigensystem of C (N-by-N) is known explicitly. If t is an Nth
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
732 ## root of unity, then the inner product of V with W = [1 t t^2 ... t^N]
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
733 ## is an eigenvalue of C, and W(N:-1:1) is an eigenvector of C.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
734 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
735 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
736 ## P.J. Davis, Circulant Matrices, John Wiley, 1977.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
737
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
738 if (nargin != 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
739 error ("gallery: 1 argument is required for circul matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
740 elseif (! isnumeric (v))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
741 error ("gallery: V must be numeric for circul matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
742 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
743
16734
67b67fc0969a gallery: fix bug from typo in variable name
Carnë Draug <carandraug@octave.org>
parents: 16634
diff changeset
744 n = numel (v);
67b67fc0969a gallery: fix bug from typo in variable name
Carnë Draug <carandraug@octave.org>
parents: 16634
diff changeset
745 if (isscalar (v) && fix (v) == v)
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
746 n = v;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
747 v = 1:n;
16734
67b67fc0969a gallery: fix bug from typo in variable name
Carnë Draug <carandraug@octave.org>
parents: 16634
diff changeset
748 elseif (n > 1 && isvector (v))
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
749 ## do nothing
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
750 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
751 error ("gallery: X must be a scalar or a vector for circul matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
752 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
753
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
754 v = v(:).'; # Make sure v is a row vector
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
755 C = toeplitz ([v(1) v(n:-1:2)], v);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
756
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
757 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
758
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
759 function A = clement (n, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
760
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
761 ## CLEMENT Clement matrix - tridiagonal with zero diagonal entries.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
762 ## CLEMENT(N, K) is a tridiagonal matrix with zero diagonal entries
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
763 ## and known eigenvalues. It is singular if N is odd. About 64
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
764 ## percent of the entries of the inverse are zero. The eigenvalues
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
765 ## are plus and minus the numbers N-1, N-3, N-5, ..., (1 or 0).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
766 ## For K = 0 (the default) the matrix is unsymmetric, while for
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
767 ## K = 1 it is symmetric.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
768 ## CLEMENT(N, 1) is diagonally similar to CLEMENT(N).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
769 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
770 ## Similar properties hold for TRIDIAG(X,Y,Z) where Y = ZEROS(N,1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
771 ## The eigenvalues still come in plus/minus pairs but they are not
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
772 ## known explicitly.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
773 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
774 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
775 ## P.A. Clement, A class of triple-diagonal matrices for test
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
776 ## purposes, SIAM Review, 1 (1959), pp. 50-52.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
777 ## A. Edelman and E. Kostlan, The road from Kac's matrix to Kac's
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
778 ## random polynomials. In John~G. Lewis, editor, Proceedings of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
779 ## the Fifth SIAM Conference on Applied Linear Algebra Society
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
780 ## for Industrial and Applied Mathematics, Philadelphia, 1994,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
781 ## pp. 503-507.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
782 ## O. Taussky and J. Todd, Another look at a matrix of Mark Kac,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
783 ## Linear Algebra and Appl., 150 (1991), pp. 341-360.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
784
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
785 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
786 error ("gallery: 1 or 2 arguments are required for clement matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
787 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
788 error ("gallery: N must be an integer for clement matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
789 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
790 error ("gallery: K must be a numeric scalar for clement matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
791 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
792
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
793 n -= 1;
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
794 x = n:-1:1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
795 z = 1:n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
796
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
797 if (k == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
798 A = diag (x, -1) + diag (z, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
799 elseif (k == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
800 y = sqrt (x.*z);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
801 A = diag (y, -1) + diag (y, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
802 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
803 error ("gallery: K must have a value of 0 or 1 for clement matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
804 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
805
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
806 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
807
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
808 function C = compar (A, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
809
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
810 ## COMP Comparison matrices.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
811 ## COMP(A) is DIAG(B) - TRIL(B,-1) - TRIU(B,1), where B = ABS(A).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
812 ## COMP(A, 1) is A with each diagonal element replaced by its
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
813 ## absolute value, and each off-diagonal element replaced by minus
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
814 ## the absolute value of the largest element in absolute value in
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
815 ## its row. However, if A is triangular COMP(A, 1) is too.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
816 ## COMP(A, 0) is the same as COMP(A).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
817 ## COMP(A) is often denoted by M(A) in the literature.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
818 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
819 ## Reference (e.g.):
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
820 ## N.J. Higham, A survey of condition number estimation for
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
821 ## triangular matrices, SIAM Review, 29 (1987), pp. 575-596.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
822
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
823 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
824 error ("gallery: 1 or 2 arguments are required for compar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
825 elseif (! isnumeric (A) || ndims (A) != 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
826 error ("gallery: A must be a 2-D matrix for compar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
827 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
828 error ("gallery: K must be a numeric scalar for compar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
829 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
830
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
831 [m, n] = size (A);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
832 p = min (m, n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
833
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
834 if (k == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
835 ## This code uses less temporary storage than
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
836 ## the 'high level' definition above.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
837 C = -abs (A);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
838 for j = 1:p
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
839 C(j,j) = abs (A(j,j));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
840 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
841
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
842 elseif (k == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
843 C = A';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
844 for j = 1:p
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
845 C(k,k) = 0;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
846 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
847 mx = max (abs (C));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
848 C = -mx'*ones (1, n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
849 for j = 1:p
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
850 C(j,j) = abs (A(j,j));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
851 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
852 if (all (A == tril (A))), C = tril (C); endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
853 if (all (A == triu (A))), C = triu (C); endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
854
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
855 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
856 error ("gallery: K must have a value of 0 or 1 for compar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
857 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
858
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
859 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
860
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
861 function A = condex (n, k = 4, theta = 100)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
862
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
863 ## CONDEX 'Counterexamples' to matrix condition number estimators.
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
864 ## CONDEX(N, K, THETA) is a 'counterexample' matrix to a condition
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
865 ## estimator. It has order N and scalar parameter THETA (default 100).
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
866 ## If N is not equal to the 'natural' size of the matrix then
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
867 ## the matrix is padded out with an identity matrix to order N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
868 ## The matrix, its natural size, and the estimator to which it applies
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
869 ## are specified by K (default K = 4) as follows:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
870 ## K = 1: 4-by-4, LINPACK (RCOND)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
871 ## K = 2: 3-by-3, LINPACK (RCOND)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
872 ## K = 3: arbitrary, LINPACK (RCOND) (independent of THETA)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
873 ## K = 4: N >= 4, SONEST (Higham 1988)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
874 ## (Note that in practice the K = 4 matrix is not usually a
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
875 ## counterexample because of the rounding errors in forming it.)
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
876 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
877 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
878 ## A.K. Cline and R.K. Rew, A set of counter-examples to three
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
879 ## condition number estimators, SIAM J. Sci. Stat. Comput.,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
880 ## 4 (1983), pp. 602-611.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
881 ## N.J. Higham, FORTRAN codes for estimating the one-norm of a real or
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
882 ## complex matrix, with applications to condition estimation
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
883 ## (Algorithm 674), ACM Trans. Math. Soft., 14 (1988), pp. 381-396.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
884
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
885 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
886 error ("gallery: 1 to 3 arguments are required for condex matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
887 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
888 error ("gallery: N must be an integer for condex matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
889 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
890 error ("gallery: K must be a numeric scalar for condex matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
891 elseif (! isnumeric (theta) || ! isscalar (theta))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
892 error ("gallery: THETA must be a numeric scalar for condex matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
893 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
894
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
895 if (k == 1) # Cline and Rew (1983), Example B.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
896 A = [1 -1 -2*theta 0
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
897 0 1 theta -theta
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
898 0 1 1+theta -(theta+1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
899 0 0 0 theta];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
900
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
901 elseif (k == 2) # Cline and Rew (1983), Example C.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
902 A = [1 1-2/theta^2 -2
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
903 0 1/theta -1/theta
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
904 0 0 1];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
905
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
906 elseif (k == 3) # Cline and Rew (1983), Example D.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
907 A = gallery ("triw", n, -1)';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
908 A(n,n) = -1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
909
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
910 elseif (k == 4) # Higham (1988), p. 390.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
911 x = ones (n, 3); # First col is e
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
912 x(2:n,2) = zeros (n-1, 1); # Second col is e(1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
913
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
914 ## Third col is special vector b in SONEST
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
915 x(:, 3) = (-1).^[0:n-1]' .* ( 1 + [0:n-1]'/(n-1) );
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
916
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
917 Q = orth (x); # Q*Q' is now the orthogonal projector onto span(e(1),e,b)).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
918 P = eye (n) - Q*Q';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
919 A = eye (n) + theta*P;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
920
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
921 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
922 error ("gallery: unknown estimator K '%d' for condex matrix", k);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
923 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
924
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
925 ## Pad out with identity as necessary.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
926 m = columns (A);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
927 if (m < n)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
928 for i = n:-1:m+1
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
929 A(i,i) = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
930 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
931 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
932
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
933 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
934
20298
ababbe103048 gallery: allow N to be a 2 element vectors for cycol matrices.
Carnë Draug <carandraug@octave.org>
parents: 20297
diff changeset
935 function A = cycol (n, k = max (round (n(end)/4), 1))
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
936
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
937 ## CYCOL Matrix whose columns repeat cyclically.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
938 ## A = CYCOL([M N], K) is an M-by-N matrix of the form A = B(1:M,1:N)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
939 ## where B = [C C C...] and C = RANDN(M, K). Thus A's columns repeat
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
940 ## cyclically, and A has rank at most K. K need not divide N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
941 ## K defaults to ROUND(N/4).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
942 ## CYCOL(N, K), where N is a scalar, is the same as CYCOL([N N], K).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
943 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
944 ## This type of matrix can lead to underflow problems for Gaussian
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
945 ## elimination: see NA Digest Volume 89, Issue 3 (January 22, 1989).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
946
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
947 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
948 error ("gallery: 1 or 2 arguments are required for cycol matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
949 elseif (! isnumeric (n) || all (numel (n) != [1 2]) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
950 error ("gallery: N must be a 1 or 2 element integer for cycol matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
951 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
952 error ("gallery: K must be a scalar for cycol matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
953 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
954
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
955 ## Parameter n specifies dimension: m-by-n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
956 m = n(1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
957 n = n(end);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
958
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
959 A = randn (m, k);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
960 for i = 2:ceil (n/k)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
961 A = [A A(:,1:k)];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
962 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
963 A = A(:,1:n);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
964
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
965 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
966
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
967 function [c, d, e] = dorr (n, theta = 0.01)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
968
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
969 ## DORR Dorr matrix - diagonally dominant, ill conditioned, tridiagonal.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
970 ## [C, D, E] = DORR(N, THETA) returns the vectors defining a row diagonally
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
971 ## dominant, tridiagonal M-matrix that is ill conditioned for small
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
972 ## values of the parameter THETA >= 0.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
973 ## If only one output parameter is supplied then
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
974 ## C = FULL(TRIDIAG(C,D,E)), i.e., the matrix iself is returned.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
975 ## The columns of INV(C) vary greatly in norm. THETA defaults to 0.01.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
976 ## The amount of diagonal dominance is given by (ignoring rounding errors):
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
977 ## COMP(C)*ONES(N,1) = THETA*(N+1)^2 * [1 0 0 ... 0 1]'.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
978 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
979 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
980 ## F.W. Dorr, An example of ill-conditioning in the numerical
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
981 ## solution of singular perturbation problems, Math. Comp., 25 (1971),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
982 ## pp. 271-283.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
983
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
984 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
985 error ("gallery: 1 or 2 arguments are required for dorr matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
986 elseif (! isscalar (n) || ! isnumeric (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
987 error ("gallery: N must be an integer for dorr matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
988 elseif (! isscalar (theta) || ! isnumeric (theta))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
989 error ("gallery: THETA must be a numeric scalar for dorr matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
990 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
991
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
992 c = zeros (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
993 e = c;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
994 d = c;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
995 ## All length n for convenience. Make c, e of length n-1 later.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
996
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
997 h = 1/(n+1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
998 m = floor ((n+1)/2);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
999 term = theta/h^2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1000
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1001 i = (1:m)';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1002 c(i) = -term * ones (m, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1003 e(i) = c(i) - (0.5-i*h)/h;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1004 d(i) = -(c(i) + e(i));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1005
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1006 i = (m+1:n)';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1007 e(i) = -term * ones (n-m, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1008 c(i) = e(i) + (0.5-i*h)/h;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1009 d(i) = -(c(i) + e(i));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1010
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1011 c = c(2:n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1012 e = e(1:n-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1013
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1014 if (nargout <= 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1015 c = tridiag (c, d, e);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1016 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1017
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1018 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1019
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1020 function A = dramadah (n, k = 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1021
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1022 ## DRAMADAH A (0,1) matrix whose inverse has large integer entries.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1023 ## An anti-Hadamard matrix A is a matrix with elements 0 or 1 for
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1024 ## which MU(A) := NORM(INV(A),'FRO') is maximal.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1025 ## A = DRAMADAH(N, K) is an N-by-N (0,1) matrix for which MU(A) is
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1026 ## relatively large, although not necessarily maximal.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1027 ## Available types (the default is K = 1):
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1028 ## K = 1: A is Toeplitz, with ABS(DET(A)) = 1, and MU(A) > c(1.75)^N,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1029 ## where c is a constant.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1030 ## K = 2: A is upper triangular and Toeplitz.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1031 ## The inverses of both types have integer entries.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1032 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1033 ## Another interesting (0,1) matrix:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1034 ## K = 3: A has maximal determinant among (0,1) lower Hessenberg
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1035 ## matrices: det(A) = the n'th Fibonacci number. A is Toeplitz.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1036 ## The eigenvalues have an interesting distribution in the complex
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1037 ## plane.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1038 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1039 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1040 ## R.L. Graham and N.J.A. Sloane, Anti-Hadamard matrices,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1041 ## Linear Algebra and Appl., 62 (1984), pp. 113-137.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1042 ## L. Ching, The maximum determinant of an nxn lower Hessenberg
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1043 ## (0,1) matrix, Linear Algebra and Appl., 183 (1993), pp. 147-153.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1044
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1045 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1046 error ("gallery: 1 to 2 arguments are required for dramadah matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1047 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1048 error ("gallery: N must be an integer for dramadah matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1049 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1050 error ("gallery: K must be a numeric scalar for dramadah matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1051 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1052
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1053 switch (k)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1054 case (1) # Toeplitz
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1055 c = ones (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1056 for i = 2:4:n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1057 m = min (1, n-i);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1058 c(i:i+m) = zeros (m+1, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1059 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1060 r = zeros (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1061 r(1:4) = [1 1 0 1];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1062 if (n < 4)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1063 r = r(1:n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1064 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1065 A = toeplitz (c, r);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1066
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1067 case (2) # Upper triangular and Toeplitz
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1068 c = zeros (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1069 c(1) = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1070 r = ones (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1071 for i= 3:2:n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1072 r(i) = 0;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1073 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1074 A = toeplitz (c, r);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1075
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1076 case (3) # Lower Hessenberg
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1077 c = ones (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1078 for i= 2:2:n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1079 c(i) = 0;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1080 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1081 A = toeplitz (c, [1 1 zeros(1,n-2)]);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1082
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1083 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1084 error ("gallery: unknown K '%d' for dramadah matrix", k);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1085 endswitch
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1086
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1087 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1088
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1089 function A = fiedler (c)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1090
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1091 ## FIEDLER Fiedler matrix - symmetric.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1092 ## FIEDLER(C), where C is an n-vector, is the n-by-n symmetric
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1093 ## matrix with elements ABS(C(i)-C(j)).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1094 ## Special case: if C is a scalar, then A = FIEDLER(1:C)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1095 ## (i.e. A(i,j) = ABS(i-j)).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1096 ## Properties:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1097 ## FIEDLER(N) has a dominant positive eigenvalue and all the other
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1098 ## eigenvalues are negative (Szego, 1936).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1099 ## Explicit formulas for INV(A) and DET(A) are given by Todd (1977)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1100 ## and attributed to Fiedler. These indicate that INV(A) is
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1101 ## tridiagonal except for nonzero (1,n) and (n,1) elements.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1102 ## [I think these formulas are valid only if the elements of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1103 ## C are in increasing or decreasing order---NJH.]
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1104 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1105 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1106 ## G. Szego, Solution to problem 3705, Amer. Math. Monthly,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1107 ## 43 (1936), pp. 246-259.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1108 ## J. Todd, Basic Numerical Mathematics, Vol. 2: Numerical Algebra,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1109 ## Birkhauser, Basel, and Academic Press, New York, 1977, p. 159.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1110
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1111 if (nargin != 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1112 error ("gallery: 1 argument is required for fiedler matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1113 elseif (! isnumeric (c))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1114 error ("gallery: C must be numeric for fiedler matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1115 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1116
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1117 n = numel (c);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1118 if (isscalar (c) && fix (c) == c)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1119 n = c;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1120 c = 1:n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1121 elseif (n > 1 && isvector (c))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1122 ## do nothing
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1123 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1124 error ("gallery: C must be an integer or a vector for fiedler matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1125 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1126 c = c(:).'; # Ensure c is a row vector.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1127
23381
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
1128 A = abs (c - c.');
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1129
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1130 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1131
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1132 function A = forsythe (n, alpha = sqrt (eps), lambda = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1133
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1134 ## FORSYTHE Forsythe matrix - a perturbed Jordan block.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1135 ## FORSYTHE(N, ALPHA, LAMBDA) is the N-by-N matrix equal to
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1136 ## JORDBLOC(N, LAMBDA) except it has an ALPHA in the (N,1) position.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1137 ## It has the characteristic polynomial
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1138 ## DET(A-t*EYE) = (LAMBDA-t)^N - (-1)^N ALPHA.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1139 ## ALPHA defaults to SQRT(EPS) and LAMBDA to 0.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1140
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1141 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1142 error ("gallery: 1 to 3 arguments are required for forsythe matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1143 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1144 error ("gallery: N must be an integer for forsythe matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1145 elseif (! isnumeric (alpha) || ! isscalar (alpha))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1146 error ("gallery: ALPHA must be a numeric scalar for forsythe matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1147 elseif (! isnumeric (lambda) || ! isscalar (lambda))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1148 error ("gallery: LAMBDA must be a numeric scalar for forsythe matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1149 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1150
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1151 A = jordbloc (n, lambda);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1152 A(n,1) = alpha;
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1153
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1154 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1155
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1156 function F = frank (n, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1157
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1158 ## FRANK Frank matrix---ill conditioned eigenvalues.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1159 ## F = FRANK(N, K) is the Frank matrix of order N. It is upper
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1160 ## Hessenberg with determinant 1. K = 0 is the default; if K = 1 the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1161 ## elements are reflected about the anti-diagonal (1,N)--(N,1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1162 ## F has all positive eigenvalues and they occur in reciprocal pairs
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1163 ## (so that 1 is an eigenvalue if N is odd).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1164 ## The eigenvalues of F may be obtained in terms of the zeros of the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1165 ## Hermite polynomials.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1166 ## The FLOOR(N/2) smallest eigenvalues of F are ill conditioned,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1167 ## the more so for bigger N.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1168 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1169 ## DET(FRANK(N)') comes out far from 1 for large N---see Frank (1958)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1170 ## and Wilkinson (1960) for discussions.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1171 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1172 ## This version incorporates improvements suggested by W. Kahan.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1173 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1174 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1175 ## W.L. Frank, Computing eigenvalues of complex matrices by determinant
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1176 ## evaluation and by methods of Danilewski and Wielandt, J. Soc.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1177 ## Indust. Appl. Math., 6 (1958), pp. 378-392 (see pp. 385, 388).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1178 ## G.H. Golub and J.H. Wilkinson, Ill-conditioned eigensystems and the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1179 ## computation of the Jordan canonical form, SIAM Review, 18 (1976),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1180 ## pp. 578-619 (Section 13).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1181 ## H. Rutishauser, On test matrices, Programmation en Mathematiques
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1182 ## Numeriques, Editions Centre Nat. Recherche Sci., Paris, 165,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1183 ## 1966, pp. 349-365. Section 9.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1184 ## J.H. Wilkinson, Error analysis of floating-point computation,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1185 ## Numer. Math., 2 (1960), pp. 319-340 (Section 8).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1186 ## J.H. Wilkinson, The Algebraic Eigenvalue Problem, Oxford University
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1187 ## Press, 1965 (pp. 92-93).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1188 ## The next two references give details of the eigensystem, as does
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1189 ## Rutishauser (see above).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1190 ## P.J. Eberlein, A note on the matrices denoted by B_n, SIAM J. Appl.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1191 ## Math., 20 (1971), pp. 87-92.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1192 ## J.M. Varah, A generalization of the Frank matrix, SIAM J. Sci. Stat.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1193 ## Comput., 7 (1986), pp. 835-839.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1194
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1195 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1196 error ("gallery: 1 to 2 arguments are required for frank matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1197 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1198 error ("gallery: N must be an integer for frank matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1199 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1200 error ("gallery: K must be a numeric scalar for frank matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1201 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1202
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1203 p = n:-1:1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1204 F = triu (p(ones (n, 1), :) - diag (ones (n-1, 1), -1), -1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1205
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1206 switch (k)
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
1207 case 0, # do nothing
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
1208 case 1, F = F(p,p)';
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1209 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1210 error ("gallery: K must have a value of 0 or 1 for frank matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1211 endswitch
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1212
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1213 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1214
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1215 function c = gcdmat (n)
31548
c8ad083a5802 maint: Clean up m-files before Octave 8.1 release.
Rik <rik@octave.org>
parents: 30564
diff changeset
1216
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1217 if (nargin != 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1218 error ("gallery: 1 argument is required for gcdmat matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1219 elseif (! isscalar (n) || ! isnumeric (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1220 error ("gallery: N must be an integer for gcdmat matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1221 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1222 c = gcd (repmat ((1:n)', [1 n]), repmat (1:n, [n 1]));
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1223
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1224 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1225
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1226 function A = gearmat (n, i = n, j = -n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1227
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1228 ## NOTE: this function was named gearm in the original Test Matrix Toolbox
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1229 ## GEARMAT Gear matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1230 ## A = GEARMAT(N,I,J) is the N-by-N matrix with ones on the sub- and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1231 ## super-diagonals, SIGN(I) in the (1,ABS(I)) position, SIGN(J)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1232 ## in the (N,N+1-ABS(J)) position, and zeros everywhere else.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1233 ## Defaults: I = N, j = -N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1234 ## All eigenvalues are of the form 2*COS(a) and the eigenvectors
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1235 ## are of the form [SIN(w+a), SIN(w+2a), ..., SIN(w+Na)].
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1236 ## The values of a and w are given in the reference below.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1237 ## A can have double and triple eigenvalues and can be defective.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1238 ## GEARMAT(N) is singular.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1239 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1240 ## (GEAR is a Simulink function, hence GEARMAT for Gear matrix.)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1241 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1242 ## C.W. Gear, A simple set of test matrices for eigenvalue programs,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1243 ## Math. Comp., 23 (1969), pp. 119-125.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1244
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1245 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1246 error ("gallery: 1 to 3 arguments are required for gearmat matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1247 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1248 error ("gallery: N must be an integer for gearmat matrix");
20294
2102c4582e32 gallery: fix chebspec, cycol, gearmat, hanowa, lauchli, and pei (bug #45466)
Massimiliano Fasi <massimiliano.fasi@gmail.com>
parents: 20231
diff changeset
1249 elseif (! isnumeric (i) || ! isscalar (i) || i == 0 || abs (i) > n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1250 error ("gallery: I must be a nonzero scalar, and abs (I) <= N for gearmat matrix");
20294
2102c4582e32 gallery: fix chebspec, cycol, gearmat, hanowa, lauchli, and pei (bug #45466)
Massimiliano Fasi <massimiliano.fasi@gmail.com>
parents: 20231
diff changeset
1251 elseif (! isnumeric (j) || ! isscalar (j) || i == 0 || abs (j) > n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1252 error ("gallery: J must be a nonzero scalar, and abs (J) <= N for gearmat matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1253 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1254
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1255 A = diag (ones (n-1, 1), -1) + diag (ones (n-1, 1), 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1256 A(1, abs (i)) = sign (i);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1257 A(n, n+1 - abs (j)) = sign (j);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1258
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1259 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1260
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1261 function G = grcar (n, k = 3)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1262
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1263 ## GRCAR Grcar matrix - a Toeplitz matrix with sensitive eigenvalues.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1264 ## GRCAR(N, K) is an N-by-N matrix with -1s on the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1265 ## subdiagonal, 1s on the diagonal, and K superdiagonals of 1s.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1266 ## The default is K = 3. The eigenvalues of this matrix form an
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1267 ## interesting pattern in the complex plane (try PS(GRCAR(32))).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1268 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1269 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1270 ## J.F. Grcar, Operator coefficient methods for linear equations,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1271 ## Report SAND89-8691, Sandia National Laboratories, Albuquerque,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1272 ## New Mexico, 1989 (Appendix 2).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1273 ## N.M. Nachtigal, L. Reichel and L.N. Trefethen, A hybrid GMRES
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1274 ## algorithm for nonsymmetric linear systems, SIAM J. Matrix Anal.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1275 ## Appl., 13 (1992), pp. 796-825.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1276
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1277 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1278 error ("gallery: 1 to 2 arguments are required for grcar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1279 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1280 error ("gallery: N must be an integer for grcar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1281 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1282 error ("gallery: K must be a numeric scalar for grcar matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1283 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1284
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1285 G = tril (triu (ones (n)), k) - diag (ones (n-1, 1), -1);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1286
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1287 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1288
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1289 function A = hanowa (n, d = -1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1290
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1291 ## HANOWA A matrix whose eigenvalues lie on a vertical line in the complex plane.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1292 ## HANOWA(N, d) is the N-by-N block 2x2 matrix (thus N = 2M must be even)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1293 ## [d*EYE(M) -DIAG(1:M)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1294 ## DIAG(1:M) d*EYE(M)]
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1295 ## It has complex eigenvalues lambda(k) = d +/- k*i (1 <= k <= M).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1296 ## Parameter d defaults to -1.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1297 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1298 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1299 ## E. Hairer, S.P. Norsett and G. Wanner, Solving Ordinary
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1300 ## Differential Equations I: Nonstiff Problems, Springer-Verlag,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1301 ## Berlin, 1987. (pp. 86-87)
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1302
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1303 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1304 error ("gallery: 1 to 2 arguments are required for hanowa matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1305 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1306 error ("gallery: N must be an integer for hanowa matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1307 elseif (rem (n, 2) != 0)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1308 error ("gallery: N must be even for hanowa matrix");
20294
2102c4582e32 gallery: fix chebspec, cycol, gearmat, hanowa, lauchli, and pei (bug #45466)
Massimiliano Fasi <massimiliano.fasi@gmail.com>
parents: 20231
diff changeset
1309 elseif (! isnumeric (d) || ! isscalar (d))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1310 error ("gallery: D must be a numeric scalar for hanowa matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1311 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1312
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1313 m = n/2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1314 A = [ d*eye(m) -diag(1:m)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1315 diag(1:m) d*eye(m) ];
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1316
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1317 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1318
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1319 function [v, beta] = house (x)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1320
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1321 ## HOUSE Householder matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1322 ## If [v, beta] = HOUSE(x) then H = EYE - beta*v*v' is a Householder
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1323 ## matrix such that Hx = -sign(x(1))*norm(x)*e_1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1324 ## NB: If x = 0 then v = 0, beta = 1 is returned.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1325 ## x can be real or complex.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1326 ## sign(x) := exp(i*arg(x)) ( = x./abs(x) when x ~= 0).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1327 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1328 ## Theory: (textbook references Golub & Van Loan 1989, 38-43;
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1329 ## Stewart 1973, 231-234, 262; Wilkinson 1965, 48-50).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1330 ## Hx = y: (I - beta*v*v')x = -s*e_1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1331 ## Must have |s| = norm(x), v = x+s*e_1, and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1332 ## x'y = x'Hx =(x'Hx)' real => arg(s) = arg(x(1)).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1333 ## So take s = sign(x(1))*norm(x) (which avoids cancellation).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1334 ## v'v = (x(1)+s)^2 + x(2)^2 + ... + x(n)^2
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1335 ## = 2*norm(x)*(norm(x) + |x(1)|).
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
1336 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1337 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1338 ## G.H. Golub and C.F. Van Loan, Matrix Computations, second edition,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1339 ## Johns Hopkins University Press, Baltimore, Maryland, 1989.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1340 ## G.W. Stewart, Introduction to Matrix Computations, Academic Press,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1341 ## New York, 1973,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1342 ## J.H. Wilkinson, The Algebraic Eigenvalue Problem, Oxford University
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1343 ## Press, 1965.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1344
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1345 if (nargin != 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1346 error ("gallery: 1 argument is required for house matrix");
20295
557979395ca9 gallery: allow single element vectors for 'house'.
Carnë Draug <carandraug@octave.org>
parents: 20294
diff changeset
1347 elseif (! isnumeric (x) || ! isvector (x))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1348 error ("gallery: X must be a vector for house matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1349 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1350
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1351 ## must be a column vector
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1352 x = x(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1353
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1354 s = norm (x) * (sign (x(1)) + (x(1) == 0)); # Modification for sign (0) == 1.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1355 v = x;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1356 if (s == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1357 ## Quit if x is the zero vector.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1358 beta = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1359 else
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1360 v(1) = v(1) + s;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1361 beta = 1/(s'*v(1)); # NB the conjugated s.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1362 ## beta = 1/(abs (s) * (abs (s) +abs(x(1)) would guarantee beta real.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1363 ## But beta as above can be non-real (due to rounding) only when x is complex.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1364 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1365
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1366 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1367
16980
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1368 function A = integerdata (varargin)
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1369
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1370 if (nargin < 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1371 error ("gallery: At least 3 arguments required for integerdata matrix");
16980
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1372 endif
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1373
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1374 if (isnumeric (varargin{end}))
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1375 jidx = varargin{end};
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1376 svec = [varargin{:}];
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1377 varargin(end) = [];
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1378 elseif (ischar (varargin{end}))
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1379 if (nargin < 4)
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1380 error (["gallery: CLASS argument requires 4 inputs " ...
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1381 "for integerdata matrix."]);
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1382 endif
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1383 jidx = varargin{end-1};
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1384 svec = [varargin{1:end-1}];
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1385 varargin(end-1) = [];
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
1386 else
16980
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1387 error (["gallery: J must be an integer in the range [0, 2^32-1] " ...
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1388 "for integerdata matrix"]);
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1389 endif
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1390
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1391 if (! (isnumeric (jidx) && isscalar (jidx)
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1392 && jidx == fix (jidx)
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1393 && jidx >= 0 && jidx <= 0xFFFFFFFF))
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1394 error (["gallery: J must be an integer in the range [0, 2^32-1] " ...
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1395 "for integerdata matrix"]);
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1396 endif
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1397
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1398 ## Save and restore random state. Initialization done so that reproducible
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1399 ## data is available from gallery depending on the jidx and size vector.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
1400 randstate = rand ("state");
16980
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1401 unwind_protect
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1402 rand ("state", svec);
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1403 A = randi (varargin{:});
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1404 unwind_protect_cleanup
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1405 rand ("state", randstate);
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1406 end_unwind_protect
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1407
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1408 endfunction
1909e1ed63e6 gallery.m: Add 'integerdata' matrix to function.
Rik <rik@octave.org>
parents: 16979
diff changeset
1409
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1410 function A = invhess (x, y)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1411
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1412 ## INVHESS Inverse of an upper Hessenberg matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1413 ## INVHESS(X, Y), where X is an N-vector and Y an N-1 vector,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1414 ## is the matrix whose lower triangle agrees with that of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1415 ## ONES(N,1)*X' and whose strict upper triangle agrees with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1416 ## that of [1 Y]*ONES(1,N).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1417 ## The matrix is nonsingular if X(1) ~= 0 and X(i+1) ~= Y(i)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1418 ## for all i, and its inverse is an upper Hessenberg matrix.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1419 ## If Y is omitted it defaults to -X(1:N-1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1420 ## Special case: if X is a scalar INVHESS(X) is the same as
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1421 ## INVHESS(1:X).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1422 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1423 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1424 ## F.N. Valvi and V.S. Geroyannis, Analytic inverses and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1425 ## determinants for a class of matrices, IMA Journal of Numerical
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1426 ## Analysis, 7 (1987), pp. 123-128.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1427 ## W.-L. Cao and W.J. Stewart, A note on inverses of Hessenberg-like
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1428 ## matrices, Linear Algebra and Appl., 76 (1986), pp. 233-240.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1429 ## Y. Ikebe, On inverses of Hessenberg matrices, Linear Algebra and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1430 ## Appl., 24 (1979), pp. 93-97.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1431 ## P. Rozsa, On the inverse of band matrices, Integral Equations and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1432 ## Operator Theory, 10 (1987), pp. 82-95.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1433
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1434 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1435 error ("gallery: 1 to 2 arguments are required for invhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1436 elseif (! isnumeric (x))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1437 error ("gallery: X must be numeric for invhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1438 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1439
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1440 if (isscalar (x) && fix (x) == x)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1441 n = x;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1442 x = 1:n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1443 elseif (! isscalar (x) && isvector (x))
20297
26fc9bbb8762 gallery: fix typo on variable name for invhess matrix.
Carnë Draug <carandraug@octave.org>
parents: 20296
diff changeset
1444 n = numel (x);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1445 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1446 error ("gallery: X must be an integer scalar, or a vector for invhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1447 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1448
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1449 if (nargin < 2)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1450 y = -x(1:end-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1451 elseif (! isvector (y) || numel (y) != numel (x) -1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1452 error ("gallery: Y must be a vector of length -1 than X for invhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1453 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1454
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1455 x = x(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1456 y = y(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1457
16933
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
1458 ## FIXME: On next line, z = x'; A = z(ones(n,1),:) would be more efficient.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1459 A = ones (n, 1) * x';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1460 for j = 2:n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1461 A(1:j-1,j) = y(1:j-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1462 endfor
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1463
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1464 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1465
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1466 function A = invol (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1467
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1468 ## INVOL An involutory matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1469 ## A = INVOL(N) is an N-by-N involutory (A*A = EYE(N)) and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1470 ## ill-conditioned matrix.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1471 ## It is a diagonally scaled version of HILB(N).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1472 ## NB: B = (EYE(N)-A)/2 and B = (EYE(N)+A)/2 are idempotent (B*B = B).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1473 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1474 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1475 ## A.S. Householder and J.A. Carpenter, The singular values
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1476 ## of involutory and of idempotent matrices, Numer. Math. 5 (1963),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1477 ## pp. 234-237.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1478
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
1479 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1480 error ("gallery: 1 argument is required for invol matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1481 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1482 error ("gallery: N must be an integer for invol matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1483 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1484
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1485 A = hilb (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1486
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1487 d = -n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1488 A(:, 1) = d * A(:, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1489
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1490 for i = 1:n-1
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1491 d = -(n+i)*(n-i)*d/(i*i);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1492 A(i+1,:) = d * A(i+1,:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1493 endfor
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1494
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1495 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1496
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1497 function [A, detA] = ipjfact (n, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1498
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1499 ## IPJFACT A Hankel matrix with factorial elements.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1500 ## A = IPJFACT(N, K) is the matrix with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1501 ## A(i,j) = (i+j)! (K = 0, default)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1502 ## A(i,j) = 1/(i+j)! (K = 1)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1503 ## Both are Hankel matrices.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1504 ## The determinant and inverse are known explicitly.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1505 ## If a second output argument is present, d = DET(A) is returned:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1506 ## [A, d] = IPJFACT(N, K);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1507 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1508 ## Suggested by P. R. Graves-Morris.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
1509 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1510 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1511 ## M.J.C. Gover, The explicit inverse of factorial Hankel matrices,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1512 ## Dept. of Mathematics, University of Bradford, 1993.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1513
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1514 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1515 error ("gallery: 1 to 2 arguments are required for ipjfact matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1516 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1517 error ("gallery: N must be an integer for ipjfact matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1518 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1519 error ("gallery: K must be a numeric scalar for ipjfact matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1520 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1521
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1522 c = cumprod (2:n+1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1523 d = cumprod (n+1:2*n) * c(n-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1524
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1525 A = hankel (c, d);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1526
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1527 switch (k)
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
1528 case 0, # do nothing
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
1529 case 1, A = ones (n) ./ A;
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1530 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1531 error ("gallery: K must have a value of 0 or 1 for ipjfact matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1532 endswitch
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1533
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1534 if (nargout == 2)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1535 d = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1536
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1537 if (k == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1538 for i = 1:n-1
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
1539 d *= prod (1:i+1) * prod (1:n-i);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1540 endfor
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
1541 d *= prod (1:n+1);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1542
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1543 elseif (k == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1544 for i = 0:n-1
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
1545 d *= prod (1:i) / prod (1:n+1+i);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1546 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1547 if (rem (n*(n-1)/2, 2))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1548 d = -d;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1549 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1550
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1551 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1552 error ("gallery: K must have a value of 0 or 1 for ipjfact matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1553 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1554
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1555 detA = d;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1556 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1557
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1558 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1559
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1560 function J = jordbloc (n, lambda = 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1561
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1562 ## JORDBLOC Jordan block.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1563 ## JORDBLOC(N, LAMBDA) is the N-by-N Jordan block with eigenvalue
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1564 ## LAMBDA. LAMBDA = 1 is the default.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1565
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1566 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1567 error ("gallery: 1 to 2 arguments are required for jordbloc matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1568 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1569 error ("gallery: N must be an integer for jordbloc matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1570 elseif (! isnumeric (lambda) || ! isscalar (lambda))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1571 error ("gallery: LAMBDA must be a numeric scalar for jordbloc matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1572 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1573
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1574 J = lambda * eye (n) + diag (ones (n-1, 1), 1);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1575
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1576 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1577
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1578 function U = kahan (n, theta = 1.2, pert = 25)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1579
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1580 ## KAHAN Kahan matrix - upper trapezoidal.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1581 ## KAHAN(N, THETA) is an upper trapezoidal matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1582 ## that has some interesting properties regarding estimation of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1583 ## condition and rank.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1584 ## The matrix is N-by-N unless N is a 2-vector, in which case it
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1585 ## is N(1)-by-N(2).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1586 ## The parameter THETA defaults to 1.2.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1587 ## The useful range of THETA is 0 < THETA < PI.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1588 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1589 ## To ensure that the QR factorization with column pivoting does not
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1590 ## interchange columns in the presence of rounding errors, the diagonal
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1591 ## is perturbed by PERT*EPS*diag( [N:-1:1] ).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1592 ## The default is PERT = 25, which ensures no interchanges for KAHAN(N)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1593 ## up to at least N = 90 in IEEE arithmetic.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1594 ## KAHAN(N, THETA, PERT) uses the given value of PERT.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1595 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1596 ## The inverse of KAHAN(N, THETA) is known explicitly: see
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1597 ## Higham (1987, p. 588), for example.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1598 ## The diagonal perturbation was suggested by Christian Bischof.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1599 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1600 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1601 ## W. Kahan, Numerical linear algebra, Canadian Math. Bulletin,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1602 ## 9 (1966), pp. 757-801.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1603 ## N.J. Higham, A survey of condition number estimation for
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1604 ## triangular matrices, SIAM Review, 29 (1987), pp. 575-596.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1605
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1606 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1607 error ("gallery: 1 to 3 arguments are required for kahan matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1608 elseif (! isnumeric (n) || all (numel (n) != [1 2]) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1609 error ("gallery: N must be a 1 or 2 element integer for kahan matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1610 elseif (! isnumeric (theta) || ! isscalar (theta))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1611 error ("gallery: THETA must be a numeric scalar for kahan matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1612 elseif (! isnumeric (pert) || ! isscalar (pert))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1613 error ("gallery: PERT must be a numeric scalar for kahan matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1614 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1615
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1616 ## Parameter n specifies dimension: r-by-n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1617 r = n(1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1618 n = n(end);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1619
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1620 s = sin (theta);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1621 c = cos (theta);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1622
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1623 U = eye (n) - c * triu (ones (n), 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1624 U = diag (s.^[0:n-1]) * U + pert*eps* diag ([n:-1:1]);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1625 if (r > n)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1626 U(r,n) = 0; # Extend to an r-by-n matrix
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1627 else
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1628 U = U(1:r,:); # Reduce to an r-by-n matrix
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1629 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1630
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1631 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1632
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1633 function A = kms (n, rho = 0.5)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1634
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1635 ## KMS Kac-Murdock-Szego Toeplitz matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1636 ## A = KMS(N, RHO) is the N-by-N Kac-Murdock-Szego Toeplitz matrix with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1637 ## A(i,j) = RHO^(ABS((i-j))) (for real RHO).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1638 ## If RHO is complex, then the same formula holds except that elements
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1639 ## below the diagonal are conjugated.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1640 ## RHO defaults to 0.5.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1641 ## Properties:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1642 ## A has an LDL' factorization with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1643 ## L = INV(TRIW(N,-RHO,1)'),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1644 ## D(i,i) = (1-ABS(RHO)^2)*EYE(N) except D(1,1) = 1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1645 ## A is positive definite if and only if 0 < ABS(RHO) < 1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1646 ## INV(A) is tridiagonal.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1647 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1648 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1649 ## W.F. Trench, Numerical solution of the eigenvalue problem
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1650 ## for Hermitian Toeplitz matrices, SIAM J. Matrix Analysis and Appl.,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1651 ## 10 (1989), pp. 135-146 (and see the references therein).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1652
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1653 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1654 error ("gallery: 1 to 2 arguments are required for lauchli matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1655 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1656 error ("gallery: N must be an integer for lauchli matrix");
20294
2102c4582e32 gallery: fix chebspec, cycol, gearmat, hanowa, lauchli, and pei (bug #45466)
Massimiliano Fasi <massimiliano.fasi@gmail.com>
parents: 20231
diff changeset
1657 elseif (! isscalar (rho))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1658 error ("gallery: RHO must be a scalar for lauchli matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1659 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1660
16933
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
1661 A = (1:n)'*ones (1,n);
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
1662 A = abs (A - A');
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1663 A = rho .^ A;
16933
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
1664 if (imag (rho))
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
1665 A = conj (tril (A,-1)) + triu (A);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1666 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1667
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1668 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1669
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1670 function B = krylov (A, x, j)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1671
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1672 ## KRYLOV Krylov matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1673 ## KRYLOV(A, x, j) is the Krylov matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1674 ## [x, Ax, A^2x, ..., A^(j-1)x],
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1675 ## where A is an n-by-n matrix and x is an n-vector.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1676 ## Defaults: x = ONES(n,1), j = n.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1677 ## KRYLOV(n) is the same as KRYLOV(RANDN(n)).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1678 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1679 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1680 ## G.H. Golub and C.F. Van Loan, Matrix Computations, second edition,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1681 ## Johns Hopkins University Press, Baltimore, Maryland, 1989, p. 369.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1682
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1683 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1684 error ("gallery: 1 to 3 arguments are required for krylov matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1685 elseif (! isnumeric (A) || ! issquare (A) || ndims (A) != 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1686 error ("gallery: A must be a square 2-D matrix for krylov matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1687 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1688
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1689 n = length (A);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1690 if (isscalar (A))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1691 n = A;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1692 A = randn (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1693 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1694
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1695 if (nargin < 2)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1696 x = ones (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1697 elseif (! isvector (x) || numel (x) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1698 error ("gallery: X must be a vector of length equal to A for krylov matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1699 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1700
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1701 if (nargin < 3)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1702 j = n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1703 elseif (! isnumeric (j) || ! isscalar (j) || fix (j) != j)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1704 error ("gallery: J must be an integer for krylov matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1705 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1706
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1707 B = ones (n, j);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1708 B(:,1) = x(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1709 for i = 2:j
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1710 B(:,i) = A*B(:,i-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1711 endfor
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1712
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1713 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1714
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1715 function A = lauchli (n, mu = sqrt (eps))
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1716
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1717 ## LAUCHLI Lauchli matrix - rectangular.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1718 ## LAUCHLI(N, MU) is the (N+1)-by-N matrix [ONES(1,N); MU*EYE(N))].
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1719 ## It is a well-known example in least squares and other problems
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1720 ## that indicates the dangers of forming A'*A.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1721 ## MU defaults to SQRT(EPS).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1722 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1723 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1724 ## P. Lauchli, Jordan-Elimination und Ausgleichung nach
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1725 ## kleinsten Quadraten, Numer. Math, 3 (1961), pp. 226-240.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1726
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1727 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1728 error ("gallery: 1 to 2 arguments are required for lauchli matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1729 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1730 error ("gallery: N must be an integer for lauchli matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1731 elseif (! isscalar (mu))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1732 error ("gallery: MU must be a scalar for lauchli matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1733 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1734
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1735 A = [ones(1, n)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1736 mu*eye(n) ];
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1737
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1738 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1739
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1740 function A = lehmer (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1741
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1742 ## LEHMER Lehmer matrix - symmetric positive definite.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1743 ## A = LEHMER(N) is the symmetric positive definite N-by-N matrix with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1744 ## A(i,j) = i/j for j >= i.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1745 ## A is totally nonnegative. INV(A) is tridiagonal, and explicit
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1746 ## formulas are known for its entries.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1747 ## N <= COND(A) <= 4*N*N.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1748 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1749 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1750 ## M. Newman and J. Todd, The evaluation of matrix inversion
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1751 ## programs, J. Soc. Indust. Appl. Math., 6 (1958), pp. 466-476.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1752 ## Solutions to problem E710 (proposed by D.H. Lehmer): The inverse
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1753 ## of a matrix, Amer. Math. Monthly, 53 (1946), pp. 534-535.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1754 ## J. Todd, Basic Numerical Mathematics, Vol. 2: Numerical Algebra,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1755 ## Birkhauser, Basel, and Academic Press, New York, 1977, p. 154.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1756
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
1757 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1758 error ("gallery: 1 argument is required for lehmer matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1759 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1760 error ("gallery: N must be an integer for lehmer matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1761 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1762
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1763 A = ones (n, 1) * (1:n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1764 A = A./A';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1765 A = tril (A) + tril (A, -1)';
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1766
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1767 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1768
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1769 function T = lesp (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1770
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1771 ## LESP A tridiagonal matrix with real, sensitive eigenvalues.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1772 ## LESP(N) is an N-by-N matrix whose eigenvalues are real and smoothly
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1773 ## distributed in the interval approximately [-2*N-3.5, -4.5].
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1774 ## The sensitivities of the eigenvalues increase exponentially as
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1775 ## the eigenvalues grow more negative.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1776 ## The matrix is similar to the symmetric tridiagonal matrix with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1777 ## the same diagonal entries and with off-diagonal entries 1,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1778 ## via a similarity transformation with D = diag(1!,2!,...,N!).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1779 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1780 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1781 ## H.W.J. Lenferink and M.N. Spijker, On the use of stability regions in
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1782 ## the numerical analysis of initial value problems,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1783 ## Math. Comp., 57 (1991), pp. 221-237.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1784 ## L.N. Trefethen, Pseudospectra of matrices, in Numerical Analysis 1991,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1785 ## Proceedings of the 14th Dundee Conference,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1786 ## D.F. Griffiths and G.A. Watson, eds, Pitman Research Notes in
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1787 ## Mathematics, volume 260, Longman Scientific and Technical, Essex,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1788 ## UK, 1992, pp. 234-266.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1789
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
1790 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1791 error ("gallery: 1 argument is required for lesp matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1792 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1793 error ("gallery: N must be an integer for lesp matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1794 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1795
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1796 x = 2:n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1797 T = full (tridiag (ones (size (x)) ./x, -(2*[x n+1]+1), x));
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1798
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1799 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1800
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1801 function A = lotkin (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1802
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1803 ## LOTKIN Lotkin matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1804 ## A = LOTKIN(N) is the Hilbert matrix with its first row altered to
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1805 ## all ones. A is unsymmetric, ill-conditioned, and has many negative
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1806 ## eigenvalues of small magnitude.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1807 ## The inverse has integer entries and is known explicitly.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1808 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1809 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1810 ## M. Lotkin, A set of test matrices, MTAC, 9 (1955), pp. 153-161.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1811
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
1812 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1813 error ("gallery: 1 argument is required for lotkin matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1814 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1815 error ("gallery: N must be an integer for lotkin matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1816 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1817
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1818 A = hilb (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1819 A(1,:) = ones (1, n);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1820
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1821 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1822
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1823 function A = minij (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1824
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1825 ## MINIJ Symmetric positive definite matrix MIN(i,j).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1826 ## A = MINIJ(N) is the N-by-N symmetric positive definite matrix with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1827 ## A(i,j) = MIN(i,j).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1828 ## Properties, variations:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1829 ## INV(A) is tridiagonal: it is minus the second difference matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1830 ## except its (N,N) element is 1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1831 ## 2*A-ONES(N) (Givens' matrix) has tridiagonal inverse and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1832 ## eigenvalues .5*sec^2([2r-1)PI/4N], r=1:N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1833 ## (N+1)*ONES(N)-A also has a tridiagonal inverse.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1834 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1835 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1836 ## J. Todd, Basic Numerical Mathematics, Vol. 2: Numerical Algebra,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1837 ## Birkhauser, Basel, and Academic Press, New York, 1977, p. 158.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1838 ## D.E. Rutherford, Some continuant determinants arising in physics and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1839 ## chemistry---II, Proc. Royal Soc. Edin., 63, A (1952), pp. 232-241.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1840 ## (For the eigenvalues of Givens' matrix.)
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1841
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
1842 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1843 error ("gallery: 1 argument is required for minij matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1844 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1845 error ("gallery: N must be an integer for minij matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1846 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1847
19944
941e782d0429 gallery: performance increase for minij matrix.
Carnë Draug <carandraug@octave.org>
parents: 19833
diff changeset
1848 A = bsxfun (@min, 1:n, (1:n)');
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1849
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1850 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1851
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1852 function A = moler (n, alpha = -1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1853
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1854 ## MOLER Moler matrix - symmetric positive definite.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1855 ## A = MOLER(N, ALPHA) is the symmetric positive definite N-by-N matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1856 ## U'*U where U = TRIW(N, ALPHA).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1857 ## For ALPHA = -1 (the default) A(i,j) = MIN(i,j)-2, A(i,i) = i.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1858 ## A has one small eigenvalue.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1859 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1860 ## Nash (1990) attributes the ALPHA = -1 matrix to Moler.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1861 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1862 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1863 ## J.C. Nash, Compact Numerical Methods for Computers: Linear
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1864 ## Algebra and Function Minimisation, second edition, Adam Hilger,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1865 ## Bristol, 1990 (Appendix 1).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1866
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1867 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1868 error ("gallery: 1 to 2 arguments are required for moler matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1869 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1870 error ("gallery: N must be an integer for moler matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1871 elseif (! isscalar (alpha))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1872 error ("gallery: ALPHA must be a scalar for moler matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1873 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1874
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1875 A = triw (n, alpha)' * triw (n, alpha);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1876
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1877 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1878
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1879 function [A, T] = neumann (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1880
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1881 ## NEUMANN Singular matrix from the discrete Neumann problem (sparse).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1882 ## NEUMANN(N) is the singular, row diagonally dominant matrix resulting
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1883 ## from discretizing the Neumann problem with the usual five point
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1884 ## operator on a regular mesh.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1885 ## It has a one-dimensional null space with null vector ONES(N,1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1886 ## The dimension N should be a perfect square, or else a 2-vector,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1887 ## in which case the dimension of the matrix is N(1)*N(2).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1888 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1889 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1890 ## R.J. Plemmons, Regular splittings and the discrete Neumann
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1891 ## problem, Numer. Math., 25 (1976), pp. 153-161.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1892
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
1893 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1894 error ("gallery: 1 argument is required for neumann matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1895 elseif (! isnumeric (n) || all (numel (n) != [1 2]) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1896 error ("gallery: N must be a 1 or 2 element integer for neumann matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1897 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1898
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1899 if (isscalar (n))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1900 m = sqrt (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1901 if (m^2 != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1902 error ("gallery: N must be a perfect square for neumann matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1903 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1904 n(1) = m;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1905 n(2) = m;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1906 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1907
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1908 T = tridiag (n(1), -1, 2, -1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1909 T(1,2) = -2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1910 T(n(1),n(1)-1) = -2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1911
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1912 A = kron (T, eye (n(2))) + kron (eye (n(2)), T);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1913
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1914 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1915
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1916 function A = normaldata (varargin)
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1917
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1918 if (nargin < 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1919 error ("gallery: At least 2 arguments required for normaldata matrix");
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1920 endif
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1921 if (isnumeric (varargin{end}))
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1922 jidx = varargin{end};
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1923 svec = [varargin{:}];
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1924 varargin(end) = [];
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1925 elseif (ischar (varargin{end}))
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1926 if (nargin < 3)
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1927 error (["gallery: CLASS argument requires 3 inputs " ...
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1928 "for normaldata matrix."]);
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1929 endif
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1930 jidx = varargin{end-1};
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1931 svec = [varargin{1:end-1}];
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1932 varargin(end-1) = [];
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
1933 else
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1934 error (["gallery: J must be an integer in the range [0, 2^32-1] " ...
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1935 "for normaldata matrix"]);
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1936 endif
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1937
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1938 if (! (isnumeric (jidx) && isscalar (jidx)
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1939 && jidx == fix (jidx)
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1940 && jidx >= 0 && jidx <= 0xFFFFFFFF))
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1941 error (["gallery: J must be an integer in the range [0, 2^32-1] " ...
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1942 "for normaldata matrix"]);
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1943 endif
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1944
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1945 ## Save and restore random state. Initialization done so that reproducible
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1946 ## data is available from gallery depending on the jidx and size vector.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
1947 randstate = randn ("state");
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1948 unwind_protect
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1949 randn ("state", svec);
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1950 A = randn (varargin{:});
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1951 unwind_protect_cleanup
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1952 randn ("state", randstate);
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1953 end_unwind_protect
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1954
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1955 endfunction
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
1956
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1957 function Q = orthog (n, k = 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
1958
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1959 ## ORTHOG Orthogonal and nearly orthogonal matrices.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1960 ## Q = ORTHOG(N, K) selects the K'th type of matrix of order N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1961 ## K > 0 for exactly orthogonal matrices, K < 0 for diagonal scalings of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1962 ## orthogonal matrices.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1963 ## Available types: (K = 1 is the default)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1964 ## K = 1: Q(i,j) = SQRT(2/(n+1)) * SIN( i*j*PI/(n+1) )
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1965 ## Symmetric eigenvector matrix for second difference matrix.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1966 ## K = 2: Q(i,j) = 2/SQRT(2*n+1)) * SIN( 2*i*j*PI/(2*n+1) )
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1967 ## Symmetric.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1968 ## K = 3: Q(r,s) = EXP(2*PI*i*(r-1)*(s-1)/n) / SQRT(n) (i=SQRT(-1))
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1969 ## Unitary, the Fourier matrix. Q^4 is the identity.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1970 ## This is essentially the same matrix as FFT(EYE(N))/SQRT(N)!
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1971 ## K = 4: Helmert matrix: a permutation of a lower Hessenberg matrix,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1972 ## whose first row is ONES(1:N)/SQRT(N).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1973 ## K = 5: Q(i,j) = SIN( 2*PI*(i-1)*(j-1)/n ) + COS( 2*PI*(i-1)*(j-1)/n ).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1974 ## Symmetric matrix arising in the Hartley transform.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1975 ## K = -1: Q(i,j) = COS( (i-1)*(j-1)*PI/(n-1) )
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1976 ## Chebyshev Vandermonde-like matrix, based on extrema of T(n-1).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1977 ## K = -2: Q(i,j) = COS( (i-1)*(j-1/2)*PI/n) )
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1978 ## Chebyshev Vandermonde-like matrix, based on zeros of T(n).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1979 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1980 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1981 ## N.J. Higham and D.J. Higham, Large growth factors in Gaussian
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1982 ## elimination with pivoting, SIAM J. Matrix Analysis and Appl.,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1983 ## 10 (1989), pp. 155-164.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1984 ## P. Morton, On the eigenvectors of Schur's matrix, J. Number Theory,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1985 ## 12 (1980), pp. 122-127. (Re. ORTHOG(N, 3))
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1986 ## H.O. Lancaster, The Helmert Matrices, Amer. Math. Monthly, 72 (1965),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1987 ## pp. 4-12.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1988 ## D. Bini and P. Favati, On a matrix algebra related to the discrete
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1989 ## Hartley transform, SIAM J. Matrix Anal. Appl., 14 (1993),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
1990 ## pp. 500-507.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1991
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1992 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1993 error ("gallery: 1 to 2 arguments are required for orthog matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1994 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1995 error ("gallery: N must be an integer for orthog matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1996 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
1997 error ("gallery: K must be a numeric scalar for orthog matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1998 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
1999
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2000 switch (k)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2001 case (1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2002 ## E'vectors second difference matrix
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2003 m = (1:n)'*(1:n) * (pi/(n+1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2004 Q = sin (m) * sqrt (2/(n+1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2005
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2006 case (2)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2007 m = (1:n)'*(1:n) * (2*pi/(2*n+1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2008 Q = sin (m) * (2/ sqrt (2*n+1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2009
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2010 case (3)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2011 ## Vandermonde based on roots of unity
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2012 m = 0:n-1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2013 Q = exp (m'*m*2*pi* sqrt (-1) / n) / sqrt (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2014
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2015 case (4)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2016 ## Helmert matrix
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2017 Q = tril (ones (n));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2018 Q(1,2:n) = ones (1, n-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2019 for i = 2:n
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2020 Q(i,i) = -(i-1);
17306
09543e9c8f40 Use explicit form of end (endif, endfor, etc.) in core m-files.
Rik <rik@octave.org>
parents: 17281
diff changeset
2021 endfor
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2022 Q = diag (sqrt ([n 1:n-1] .* [1:n])) \ Q;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2023
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2024 case (5)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2025 ## Hartley matrix
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2026 m = (0:n-1)'*(0:n-1) * (2*pi/n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2027 Q = (cos (m) + sin (m)) / sqrt (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2028
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2029 case (-1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2030 ## extrema of T(n-1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2031 m = (0:n-1)'*(0:n-1) * (pi/(n-1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2032 Q = cos (m);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2033
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2034 case (-2)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2035 ## zeros of T(n)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2036 m = (0:n-1)'*(.5:n-.5) * (pi/n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2037 Q = cos (m);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2038
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2039 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2040 error ("gallery: unknown K '%d' for orthog matrix", k);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2041 endswitch
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2042
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2043 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2044
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2045 function A = parter (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2046
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2047 ## PARTER Parter matrix - a Toeplitz matrix with singular values near PI.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2048 ## PARTER(N) is the matrix with (i,j) element 1/(i-j+0.5).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2049 ## It is a Cauchy matrix and a Toeplitz matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2050 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2051 ## At the Second SIAM Conference on Linear Algebra, Raleigh, N.C.,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2052 ## 1985, Cleve Moler noted that most of the singular values of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2053 ## PARTER(N) are very close to PI. An explanation of the phenomenon
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2054 ## was given by Parter; see also the paper by Tyrtyshnikov.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2055 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2056 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2057 ## The MathWorks Newsletter, Volume 1, Issue 1, March 1986, page 2.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2058 ## S.V. Parter, On the distribution of the singular values of Toeplitz
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2059 ## matrices, Linear Algebra and Appl., 80 (1986), pp. 115-130.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2060 ## E.E. Tyrtyshnikov, Cauchy-Toeplitz matrices and some applications,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2061 ## Linear Algebra and Appl., 149 (1991), pp. 1-18.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2062
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2063 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2064 error ("gallery: 1 argument is required for parter matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2065 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2066 error ("gallery: N must be an integer for parter matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2067 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2068
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2069 A = cauchy ((1:n) + 0.5, -(1:n));
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2070
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2071 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2072
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2073 function P = pei (n, alpha = 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2074
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2075 ## PEI Pei matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2076 ## PEI(N, ALPHA), where ALPHA is a scalar, is the symmetric matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2077 ## ALPHA*EYE(N) + ONES(N).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2078 ## If ALPHA is omitted then ALPHA = 1 is used.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2079 ## The matrix is singular for ALPHA = 0, -N.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2080 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2081 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2082 ## M.L. Pei, A test matrix for inversion procedures,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2083 ## Comm. ACM, 5 (1962), p. 508.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2084
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2085 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2086 error ("gallery: 1 to 2 arguments are required for pei matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2087 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2088 error ("gallery: N must be an integer for pei matrix");
20294
2102c4582e32 gallery: fix chebspec, cycol, gearmat, hanowa, lauchli, and pei (bug #45466)
Massimiliano Fasi <massimiliano.fasi@gmail.com>
parents: 20231
diff changeset
2089 elseif (! isnumeric (alpha) || ! isscalar (alpha))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2090 error ("gallery: ALPHA must be a scalar for pei matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2091 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2092
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2093 P = alpha * eye (n) + ones (n);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2094
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2095 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2096
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2097 function A = poisson (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2098
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2099 ## POISSON Block tridiagonal matrix from Poisson's equation (sparse).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2100 ## POISSON(N) is the block tridiagonal matrix of order N^2
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2101 ## resulting from discretizing Poisson's equation with the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2102 ## 5-point operator on an N-by-N mesh.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2103 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2104 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2105 ## G.H. Golub and C.F. Van Loan, Matrix Computations, second edition,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2106 ## Johns Hopkins University Press, Baltimore, Maryland, 1989
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2107 ## (Section 4.5.4).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2108
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2109 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2110 error ("gallery: 1 argument is required for poisson matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2111 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2112 error ("gallery: N must be an integer for poisson matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2113 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2114
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2115 S = tridiag (n, -1, 2, -1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2116 I = speye (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2117 A = kron (I, S) + kron (S, I);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2118
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2119 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2120
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2121 function A = prolate (n, w = 0.25)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2122
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2123 ## PROLATE Prolate matrix - symmetric, ill-conditioned Toeplitz matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2124 ## A = PROLATE(N, W) is the N-by-N prolate matrix with parameter W.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2125 ## It is a symmetric Toeplitz matrix.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2126 ## If 0 < W < 0.5 then
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2127 ## - A is positive definite
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2128 ## - the eigenvalues of A are distinct, lie in (0, 1), and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2129 ## tend to cluster around 0 and 1.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2130 ## W defaults to 0.25.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2131 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2132 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2133 ## J.M. Varah. The Prolate matrix. Linear Algebra and Appl.,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2134 ## 187:269--278, 1993.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2135
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2136 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2137 error ("gallery: 1 to 2 arguments are required for prolate matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2138 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2139 error ("gallery: N must be an integer for prolate matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2140 elseif (! isnumeric (w) || ! isscalar (w))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2141 error ("gallery: W must be a scalar for prolate matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2142 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2143
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2144 a = zeros (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2145 a(1) = 2*w;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2146 a(2:n) = sin (2*pi*w*(1:n-1)) ./ (pi*(1:n-1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2147
16933
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
2148 A = toeplitz (a);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2149
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2150 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2151
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2152 function H = randhess (x)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2153
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2154 ## NOTE: this function was named ohess in the original Test Matrix Toolbox
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2155 ## RANDHESS Random, orthogonal upper Hessenberg matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2156 ## H = RANDHESS(N) is an N-by-N real, random, orthogonal
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2157 ## upper Hessenberg matrix.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2158 ## Alternatively, H = RANDHESS(X), where X is an arbitrary real
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2159 ## N-vector (N > 1) constructs H non-randomly using the elements
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2160 ## of X as parameters.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2161 ## In both cases H is constructed via a product of N-1 Givens rotations.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2162 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2163 ## Note: See Gragg (1986) for how to represent an N-by-N (complex)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2164 ## unitary Hessenberg matrix with positive subdiagonal elements in terms
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2165 ## of 2N-1 real parameters (the Schur parametrization).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2166 ## This M-file handles the real case only and is intended simply as a
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2167 ## convenient way to generate random or non-random orthogonal Hessenberg
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2168 ## matrices.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2169 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2170 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2171 ## W.B. Gragg, The QR algorithm for unitary Hessenberg matrices,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2172 ## J. Comp. Appl. Math., 16 (1986), pp. 1-8.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2173
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2174 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2175 error ("gallery: 1 argument is required for randhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2176 elseif (! isnumeric (x) || ! isreal (x))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2177 error ("gallery: N or X must be numeric real values for randhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2178 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2179
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2180 if (isscalar (x))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2181 n = x;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2182 x = rand (n-1, 1) * 2*pi;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2183 H = eye (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2184 H(n,n) = sign (randn);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2185 elseif (isvector (x))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2186 n = numel (x);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2187 H = eye (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2188 H(n,n) = sign (x(n)) + (x(n) == 0); # Second term ensures H(n,n) nonzero.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2189 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2190 error ("gallery: N or X must be a scalar or a vector for randhess matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2191 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2192
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2193 for i = n:-1:2
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2194 ## Apply Givens rotation through angle x(i-1).
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2195 theta = x(i-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2196 c = cos (theta);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2197 s = sin (theta);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2198 H([i-1 i], :) = [ c*H(i-1,:)+s*H(i,:)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2199 -s*H(i-1,:)+c*H(i,:) ];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2200 endfor
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2201
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2202 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2203
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2204 function A = rando (n, k = 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2205
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2206 ## RANDO Random matrix with elements -1, 0 or 1.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2207 ## A = RANDO(N, K) is a random N-by-N matrix with elements from
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2208 ## one of the following discrete distributions (default K = 1):
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2209 ## K = 1: A(i,j) = 0 or 1 with equal probability,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2210 ## K = 2: A(i,j) = -1 or 1 with equal probability,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2211 ## K = 3: A(i,j) = -1, 0 or 1 with equal probability.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2212 ## N may be a 2-vector, in which case the matrix is N(1)-by-N(2).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2213
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2214 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2215 error ("gallery: 1 to 2 arguments are required for rando matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2216 elseif (! isnumeric (n) || all (numel (n) != [1 2]) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2217 error ("gallery: N must be an integer for rando matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2218 elseif (! isnumeric (k) || ! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2219 error ("gallery: K must be a numeric scalar for smoke matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2220 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2221
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2222 ## Parameter n specifies dimension: m-by-n.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2223 m = n(1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2224 n = n(end);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2225
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2226 switch (k)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2227 case (1), A = floor ( rand(m, n) + 0.5); # {0, 1}
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2228 case (2), A = 2*floor ( rand(m, n) + 0.5) -1; # {-1, 1}
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2229 case (3), A = round (3*rand(m, n) - 1.5); # {-1, 0, 1}
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2230 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2231 error ("gallery: unknown K '%d' for smoke matrix", k);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2232 endswitch
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2233
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2234 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2235
20296
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2236 function A = randsvd (n, kappa = sqrt (1/eps), mode = 3, kl = max (n) -1,
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2237 ku = kl)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2238
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2239 ## RANDSVD Random matrix with pre-assigned singular values.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2240 ## RANDSVD(N, KAPPA, MODE, KL, KU) is a (banded) random matrix of order N
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2241 ## with COND(A) = KAPPA and singular values from the distribution MODE.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2242 ## N may be a 2-vector, in which case the matrix is N(1)-by-N(2).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2243 ## Available types:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2244 ## MODE = 1: one large singular value,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2245 ## MODE = 2: one small singular value,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2246 ## MODE = 3: geometrically distributed singular values,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2247 ## MODE = 4: arithmetically distributed singular values,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2248 ## MODE = 5: random singular values with unif. dist. logarithm.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2249 ## If omitted, MODE defaults to 3, and KAPPA defaults to SQRT(1/EPS).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2250 ## If MODE < 0 then the effect is as for ABS(MODE) except that in the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2251 ## original matrix of singular values the order of the diagonal entries
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2252 ## is reversed: small to large instead of large to small.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2253 ## KL and KU are the lower and upper bandwidths respectively; if they
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2254 ## are omitted a full matrix is produced.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2255 ## If only KL is present, KU defaults to KL.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2256 ## Special case: if KAPPA < 0 then a random full symmetric positive
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2257 ## definite matrix is produced with COND(A) = -KAPPA and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2258 ## eigenvalues distributed according to MODE.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2259 ## KL and KU, if present, are ignored.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2260 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2261 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2262 ## N.J. Higham, Accuracy and Stability of Numerical Algorithms,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2263 ## Society for Industrial and Applied Mathematics, Philadelphia, PA,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2264 ## USA, 1996; sec. 26.3.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2265 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2266 ## This routine is similar to the more comprehensive Fortran routine xLATMS
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2267 ## in the following reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2268 ## J.W. Demmel and A. McKenney, A test matrix generation suite,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2269 ## LAPACK Working Note #9, Courant Institute of Mathematical Sciences,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2270 ## New York, 1989.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2271
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2272 if (nargin < 1 || nargin > 5)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2273 error ("gallery: 1 to 5 arguments are required for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2274 elseif (! isnumeric (n) || all (numel (n) != [1 2]) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2275 error ("gallery: N must be a 1 or 2 element integer vector for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2276 elseif (! isnumeric (kappa) || ! isscalar (kappa))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2277 error ("gallery: KAPPA must be a numeric scalar for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2278 elseif (abs (kappa) < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2279 error ("gallery: KAPPA must larger than or equal to 1 for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2280 elseif (! isnumeric (mode) || ! isscalar (mode))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2281 error ("gallery: MODE must be a numeric scalar for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2282 elseif (! isnumeric (kl) || ! isscalar (kl))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2283 error ("gallery: KL must be a numeric scalar for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2284 elseif (! isnumeric (ku) || ! isscalar (ku))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2285 error ("gallery: KU must be a numeric scalar for randsvd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2286 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2287
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2288 posdef = 0;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2289 if (kappa < 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2290 posdef = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2291 kappa = -kappa;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2292 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2293
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2294 ## Parameter n specifies dimension: m-by-n.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2295 m = n(1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2296 n = n(end);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2297 p = min ([m n]);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2298
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2299 ## If A will be a vector
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2300 if (p == 1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2301 A = randn (m, n);
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
2302 A /= norm (A);
17306
09543e9c8f40 Use explicit form of end (endif, endfor, etc.) in core m-files.
Rik <rik@octave.org>
parents: 17281
diff changeset
2303 return;
09543e9c8f40 Use explicit form of end (endif, endfor, etc.) in core m-files.
Rik <rik@octave.org>
parents: 17281
diff changeset
2304 endif
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2305
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2306 ## Set up vector sigma of singular values.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2307 switch (abs (mode))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2308 case (1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2309 sigma = ones (p, 1) ./ kappa;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2310 sigma(1) = 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2311 case (2)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2312 sigma = ones (p, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2313 sigma(p) = 1 / kappa;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2314 case (3)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2315 factor = kappa^(-1/(p-1));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2316 sigma = factor.^[0:p-1];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2317 case (4)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2318 sigma = ones (p, 1) - (0:p-1)'/(p-1)*(1-1/kappa);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2319 case (5)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2320 ## In this case cond (A) <= kappa.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2321 rand ("uniform");
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2322 sigma = exp (-rand (p, 1) * log (kappa));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2323 otherwise
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2324 error ("gallery: unknown MODE '%d' for randsvd matrix", mode);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2325 endswitch
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2326
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2327 ## Convert to diagonal matrix of singular values.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2328 if (mode < 0)
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2329 sigma = sigma(p:-1:1);
17306
09543e9c8f40 Use explicit form of end (endif, endfor, etc.) in core m-files.
Rik <rik@octave.org>
parents: 17281
diff changeset
2330 endif
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2331 sigma = diag (sigma);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2332
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2333 if (posdef)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2334 ## handle case where KAPPA was negative
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2335 Q = qmult (p);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2336 A = Q' * sigma * Q;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2337 A = (A + A') / 2; # Ensure matrix is symmetric.
17312
088d014a7fe2 Use semicolon after "return" statement in core m-files.
Rik <rik@octave.org>
parents: 17306
diff changeset
2338 return;
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2339 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2340
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2341 if (m != n)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2342 ## Expand to m-by-n diagonal matrix
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2343 sigma(m, n) = 0;
17306
09543e9c8f40 Use explicit form of end (endif, endfor, etc.) in core m-files.
Rik <rik@octave.org>
parents: 17281
diff changeset
2344 endif
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2345
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2346 if (kl == 0 && ku == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2347 ## Diagonal matrix requested - nothing more to do.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2348 A = sigma;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2349 else
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2350 ## A = U*sigma*V, where U, V are random orthogonal matrices from the
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2351 ## Haar distribution.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2352 A = qmult (sigma');
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2353 A = qmult (A');
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2354
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2355 if (kl < n-1 || ku < n-1)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2356 ## Bandwidth reduction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2357 A = bandred (A, kl, ku);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2358 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2359 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2360
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2361 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2362
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2363 function A = redheff (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2364
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2365 ## REDHEFF A (0,1) matrix of Redheffer associated with the Riemann hypothesis.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2366 ## A = REDHEFF(N) is an N-by-N matrix of 0s and 1s defined by
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2367 ## A(i,j) = 1 if j = 1 or if i divides j,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2368 ## A(i,j) = 0 otherwise.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2369 ## It has N - FLOOR(LOG2(N)) - 1 eigenvalues equal to 1,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2370 ## a real eigenvalue (the spectral radius) approximately SQRT(N),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2371 ## a negative eigenvalue approximately -SQRT(N),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2372 ## and the remaining eigenvalues are provably ``small''.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2373 ## Barrett and Jarvis (1992) conjecture that
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2374 ## ``the small eigenvalues all lie inside the unit circle
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2375 ## ABS(Z) = 1'',
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2376 ## and a proof of this conjecture, together with a proof that some
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2377 ## eigenvalue tends to zero as N tends to infinity, would yield
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2378 ## a new proof of the prime number theorem.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2379 ## The Riemann hypothesis is true if and only if
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2380 ## DET(A) = O( N^(1/2+epsilon) ) for every epsilon > 0
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2381 ## ('!' denotes factorial).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2382 ## See also RIEMANN.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2383 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2384 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2385 ## W.W. Barrett and T.J. Jarvis,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2386 ## Spectral Properties of a Matrix of Redheffer,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2387 ## Linear Algebra and Appl., 162 (1992), pp. 673-683.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2388
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2389 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2390 error ("gallery: 1 argument is required for redheff matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2391 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2392 error ("gallery: N must be an integer for redheff matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2393 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2394
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2395 i = (1:n)' * ones (1, n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2396 A = ! rem (i', i);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2397 A(:,1) = ones (n, 1);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2398
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2399 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2400
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2401 function A = riemann (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2402
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2403 ## RIEMANN A matrix associated with the Riemann hypothesis.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2404 ## A = RIEMANN(N) is an N-by-N matrix for which the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2405 ## Riemann hypothesis is true if and only if
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2406 ## DET(A) = O( N! N^(-1/2+epsilon) ) for every epsilon > 0
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2407 ## ('!' denotes factorial).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2408 ## A = B(2:N+1, 2:N+1), where
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2409 ## B(i,j) = i-1 if i divides j and -1 otherwise.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2410 ## Properties include, with M = N+1:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2411 ## Each eigenvalue E(i) satisfies ABS(E(i)) <= M - 1/M.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2412 ## i <= E(i) <= i+1 with at most M-SQRT(M) exceptions.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2413 ## All integers in the interval (M/3, M/2] are eigenvalues.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2414 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2415 ## See also REDHEFF.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2416 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2417 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2418 ## F. Roesler, Riemann's hypothesis as an eigenvalue problem,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2419 ## Linear Algebra and Appl., 81 (1986), pp. 153-198.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2420
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2421 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2422 error ("gallery: 1 argument is required for riemann matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2423 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2424 error ("gallery: N must be an integer for riemann matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2425 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2426
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
2427 n += 1;
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2428 i = (2:n)' * ones (1, n-1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2429 j = i';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2430 A = i .* (! rem (j, i)) - ones (n-1);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2431
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2432 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2433
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2434 function A = ris (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2435
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2436 ## NOTE: this function was named dingdong in the original Test Matrix Toolbox
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2437 ## RIS Dingdong matrix - a symmetric Hankel matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2438 ## A = RIS(N) is the symmetric N-by-N Hankel matrix with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2439 ## A(i,j) = 0.5/(N-i-j+1.5).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2440 ## The eigenvalues of A cluster around PI/2 and -PI/2.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2441 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2442 ## Invented by F.N. Ris.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2443 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2444 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2445 ## J.C. Nash, Compact Numerical Methods for Computers: Linear
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2446 ## Algebra and Function Minimisation, second edition, Adam Hilger,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2447 ## Bristol, 1990 (Appendix 1).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2448
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2449 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2450 error ("gallery: 1 argument is required for ris matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2451 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2452 error ("gallery: N must be an integer for ris matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2453 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2454
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2455 p = -2*(1:n) + (n+1.5);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2456 A = cauchy (p);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2457
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2458 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2459
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2460 function A = smoke (n, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2461
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2462 ## SMOKE Smoke matrix - complex, with a 'smoke ring' pseudospectrum.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2463 ## SMOKE(N) is an N-by-N matrix with 1s on the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2464 ## superdiagonal, 1 in the (N,1) position, and powers of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2465 ## roots of unity along the diagonal.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2466 ## SMOKE(N, 1) is the same except for a zero (N,1) element.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2467 ## The eigenvalues of SMOKE(N, 1) are the N'th roots of unity;
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2468 ## those of SMOKE(N) are the N'th roots of unity times 2^(1/N).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2469 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2470 ## Try PS(SMOKE(32)). For SMOKE(N, 1) the pseudospectrum looks
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2471 ## like a sausage folded back on itself.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2472 ## GERSH(SMOKE(N, 1)) is interesting.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2473 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2474 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2475 ## L. Reichel and L.N. Trefethen, Eigenvalues and pseudo-eigenvalues of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2476 ## Toeplitz matrices, Linear Algebra and Appl., 162-164:153-185, 1992.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2477
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2478 if (nargin < 1 || nargin > 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2479 error ("gallery: 1 to 2 arguments are required for smoke matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2480 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2481 error ("gallery: N must be an integer for smoke matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2482 elseif (! isnumeric (n) || ! isscalar (n))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2483 error ("gallery: K must be a numeric scalar for smoke matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2484 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2485
16933
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
2486 w = exp (2*pi*i/n);
e39f00a32dc7 maint: Use parentheses around condition for switch(),while(),if() statements.
Rik <rik@octave.org>
parents: 16816
diff changeset
2487 A = diag ( [w.^(1:n-1) 1] ) + diag (ones (n-1,1), 1);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2488
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2489 switch (k)
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
2490 case 0, A(n,1) = 1;
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31548
diff changeset
2491 case 1, # do nothing
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2492 otherwise,
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2493 error ("gallery: K must have a value of 0 or 1 for smoke matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2494 endswitch
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2495
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2496 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2497
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2498 function T = toeppd (n, m = n, w = rand (m,1), theta = rand (m,1))
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2499
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2500 ## NOTE: this function was named pdtoep in the original Test Matrix Toolbox
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2501 ## TOEPPD Symmetric positive definite Toeplitz matrix.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2502 ## TOEPPD(N, M, W, THETA) is an N-by-N symmetric positive (semi-)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2503 ## definite (SPD) Toeplitz matrix, comprised of the sum of M rank 2
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2504 ## (or, for certain THETA, rank 1) SPD Toeplitz matrices.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2505 ## Specifically,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2506 ## T = W(1)*T(THETA(1)) + ... + W(M)*T(THETA(M)),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2507 ## where T(THETA(k)) has (i,j) element COS(2*PI*THETA(k)*(i-j)).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2508 ## Defaults: M = N, W = RAND(M,1), THETA = RAND(M,1).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2509 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2510 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2511 ## G. Cybenko and C.F. Van Loan, Computing the minimum eigenvalue of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2512 ## a symmetric positive definite Toeplitz matrix, SIAM J. Sci. Stat.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2513 ## Comput., 7 (1986), pp. 123-131.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2514
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2515 if (nargin < 1 || nargin > 4)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2516 error ("gallery: 1 to 4 arguments are required for toeppd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2517 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2518 error ("gallery: N must be a numeric integer for toeppd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2519 elseif (! isnumeric (m) || ! isscalar (m) || fix (m) != m)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2520 error ("gallery: M must be a numeric integer for toeppd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2521 elseif (numel (w) != m || numel (theta) != m)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2522 error ("gallery: W and THETA must be vectors of length M for toeppd matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2523 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2524
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2525 T = zeros (n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2526 E = 2*pi * ((1:n)' * ones (1, n) - ones (n, 1) * (1:n));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2527
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2528 for i = 1:m
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20162
diff changeset
2529 T += w(i) * cos (theta(i)*E);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2530 endfor
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2531
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2532 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2533
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2534 function P = toeppen (n, a = 1, b = -10, c = 0, d = 10, e = 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2535
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2536 ## NOTE: this function was named pentoep in the original Test Matrix Toolbox
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2537 ## TOEPPEN Pentadiagonal Toeplitz matrix (sparse).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2538 ## P = TOEPPEN(N, A, B, C, D, E) is the N-by-N pentadiagonal
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2539 ## Toeplitz matrix with diagonals composed of the numbers
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2540 ## A =: P(3,1), B =: P(2,1), C =: P(1,1), D =: P(1,2), E =: P(1,3).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2541 ## Default: (A,B,C,D,E) = (1,-10,0,10,1) (a matrix of Rutishauser).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2542 ## This matrix has eigenvalues lying approximately on
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2543 ## the line segment 2*cos(2*t) + 20*i*sin(t).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2544 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2545 ## Interesting plots are
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2546 ## PS(FULL(TOEPPEN(32,0,1,0,0,1/4))) - 'triangle'
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2547 ## PS(FULL(TOEPPEN(32,0,1/2,0,0,1))) - 'propeller'
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2548 ## PS(FULL(TOEPPEN(32,0,1/2,1,1,1))) - 'fish'
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2549 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2550 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2551 ## R.M. Beam and R.F. Warming, The asymptotic spectra of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2552 ## banded Toeplitz and quasi-Toeplitz matrices, SIAM J. Sci.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2553 ## Comput. 14 (4), 1993, pp. 971-1006.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2554 ## H. Rutishauser, On test matrices, Programmation en Mathematiques
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2555 ## Numeriques, Editions Centre Nat. Recherche Sci., Paris, 165,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2556 ## 1966, pp. 349-365.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2557
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2558 if (nargin < 1 || nargin > 6)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2559 error ("gallery: 1 to 6 arguments are required for toeppen matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2560 elseif (! isnumeric (n) || ! isscalar (n) || fix (n) != n)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2561 error ("gallery: N must be a numeric integer for toeppen matrix");
30330
01de0045b2e3 maint: Shorten some long lines to <= 80 characters (bug #57599)
Rik <rik@octave.org>
parents: 30326
diff changeset
2562 elseif (any (! cellfun ("isnumeric", {a b c d e}))
01de0045b2e3 maint: Shorten some long lines to <= 80 characters (bug #57599)
Rik <rik@octave.org>
parents: 30326
diff changeset
2563 || any (cellfun ("numel", {a b c d e}) != 1))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2564 error ("gallery: A, B, C, D and E must be numeric scalars for toeppen matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2565 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2566
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2567 P = spdiags ([a*ones(n,1) b*ones(n,1) c*ones(n,1) d*ones(n,1) e*ones(n,1)],
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2568 -2:2, n, n);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2569
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2570 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2571
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2572 function T = tridiag (n, x = -1, y = 2, z = -1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2573
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2574 ## TRIDIAG Tridiagonal matrix (sparse).
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2575 ## TRIDIAG(X, Y, Z) is the tridiagonal matrix with subdiagonal X,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2576 ## diagonal Y, and superdiagonal Z.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2577 ## X and Z must be vectors of dimension one less than Y.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2578 ## Alternatively TRIDIAG(N, C, D, E), where C, D, and E are all
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2579 ## scalars, yields the Toeplitz tridiagonal matrix of order N
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2580 ## with subdiagonal elements C, diagonal elements D, and superdiagonal
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2581 ## elements E. This matrix has eigenvalues (Todd 1977)
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2582 ## D + 2*SQRT(C*E)*COS(k*PI/(N+1)), k=1:N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2583 ## TRIDIAG(N) is the same as TRIDIAG(N,-1,2,-1), which is
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2584 ## a symmetric positive definite M-matrix (the negative of the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2585 ## second difference matrix).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2586 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2587 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2588 ## J. Todd, Basic Numerical Mathematics, Vol. 2: Numerical Algebra,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2589 ## Birkhauser, Basel, and Academic Press, New York, 1977, p. 155.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2590 ## D.E. Rutherford, Some continuant determinants arising in physics and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2591 ## chemistry---II, Proc. Royal Soc. Edin., 63, A (1952), pp. 232-241.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2592
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2593 if (nargin != 1 && nargin != 3 && nargin != 4)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2594 error ("gallery: 1, 3, or 4 arguments are required for tridiag matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2595 elseif (nargin == 3)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2596 z = y;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2597 y = x;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2598 x = n;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2599 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2600
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2601 ## Force column vectors
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2602 x = x(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2603 y = y(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2604 z = z(:);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2605
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2606 if (isscalar (x) && isscalar (y) && isscalar (z))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2607 x *= ones (n-1, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2608 z *= ones (n-1, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2609 y *= ones (n, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2610 elseif (numel (y) != numel (x) + 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2611 error ("gallery: X must have one element less than Y for tridiag matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2612 elseif (numel (y) != numel (z) + 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2613 error ("gallery: Z must have one element less than Y for tridiag matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2614 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2615
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2616 ## T = diag (x, -1) + diag (y) + diag (z, 1); # For non-sparse matrix.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2617 n = numel (y);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2618 T = spdiags ([[x;0] y [0;z]], -1:1, n, n);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2619
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2620 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2621
18846
3d33fe79816c gallery.m: Return correct matrix if 3rd argument is not specified.
Rik <rik@octave.org>
parents: 18812
diff changeset
2622 function t = triw (n, alpha = -1, k = n(end) - 1)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2623
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2624 ## TRIW Upper triangular matrix discussed by Wilkinson and others.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2625 ## TRIW(N, ALPHA, K) is the upper triangular matrix with ones on
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2626 ## the diagonal and ALPHAs on the first K >= 0 superdiagonals.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2627 ## N may be a 2-vector, in which case the matrix is N(1)-by-N(2) and
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2628 ## upper trapezoidal.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2629 ## Defaults: ALPHA = -1,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2630 ## K = N - 1 (full upper triangle).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2631 ## TRIW(N) is a matrix discussed by Kahan, Golub and Wilkinson.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2632 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2633 ## Ostrowski (1954) shows that
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2634 ## COND(TRIW(N,2)) = COT(PI/(4*N))^2,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2635 ## and for large ABS(ALPHA),
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2636 ## COND(TRIW(N,ALPHA)) is approximately ABS(ALPHA)^N*SIN(PI/(4*N-2)).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2637 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2638 ## Adding -2^(2-N) to the (N,1) element makes TRIW(N) singular,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2639 ## as does adding -2^(1-N) to all elements in the first column.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2640 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2641 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2642 ## G.H. Golub and J.H. Wilkinson, Ill-conditioned eigensystems and the
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2643 ## computation of the Jordan canonical form, SIAM Review,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2644 ## 18(4), 1976, pp. 578-619.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2645 ## W. Kahan, Numerical linear algebra, Canadian Math. Bulletin,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2646 ## 9 (1966), pp. 757-801.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2647 ## A.M. Ostrowski, On the spectrum of a one-parametric family of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2648 ## matrices, J. Reine Angew. Math., 193 (3/4), 1954, pp. 143-160.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2649 ## J.H. Wilkinson, Singular-value decomposition---basic aspects,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2650 ## in D.A.H. Jacobs, ed., Numerical Software---Needs and Availability,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2651 ## Academic Press, London, 1978, pp. 109-135.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2652
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2653 if (nargin < 1 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2654 error ("gallery: 1 to 3 arguments are required for triw matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2655 elseif (! isnumeric (n) || all (numel (n) != [1 2]))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2656 error ("gallery: N must be a 1 or 2 elements vector for triw matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2657 elseif (! isscalar (alpha))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2658 error ("gallery: ALPHA must be a scalar for triw matrix");
18846
3d33fe79816c gallery.m: Return correct matrix if 3rd argument is not specified.
Rik <rik@octave.org>
parents: 18812
diff changeset
2659 elseif (! isscalar (k) || ! isnumeric (k) || fix (k) != k || k < 0)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2660 error ("gallery: K must be a numeric integer >= 0 for triw matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2661 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2662
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2663 m = n(1); # Parameter n specifies dimension: m-by-n.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2664 n = n(end);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2665
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2666 t = tril (eye (m, n) + alpha * triu (ones (m, n), 1), k);
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2667
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2668 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2669
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2670 function A = uniformdata (varargin)
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2671
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2672 if (nargin < 2)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2673 error ("gallery: At least 2 arguments required for uniformdata matrix");
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2674 endif
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2675 if (isnumeric (varargin{end}))
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2676 jidx = varargin{end};
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2677 svec = [varargin{:}];
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2678 varargin(end) = [];
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2679 elseif (ischar (varargin{end}))
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2680 if (nargin < 3)
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
2681 error (["gallery: CLASS argument requires 3 inputs " ...
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
2682 "for uniformdata matrix."]);
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2683 endif
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2684 jidx = varargin{end-1};
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2685 svec = [varargin{1:end-1}];
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2686 varargin(end-1) = [];
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2687 else
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
2688 error (["gallery: J must be an integer in the range [0, 2^32-1] " ...
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
2689 "for uniformdata matrix"]);
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2690 endif
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2691
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2692 if (! (isnumeric (jidx) && isscalar (jidx)
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2693 && jidx == fix (jidx)
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2694 && jidx >= 0 && jidx <= 0xFFFFFFFF))
16979
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
2695 error (["gallery: J must be an integer in the range [0, 2^32-1] " ...
9aa293e00475 gallery.m: Add 'normaldata' matrix to function.
Rik <rik@octave.org>
parents: 16978
diff changeset
2696 "for uniformdata matrix"]);
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2697 endif
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2698
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2699 ## Save and restore random state. Initialization done so that reproducible
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2700 ## data is available from gallery depending on the jidx and size vector.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2701 randstate = rand ("state");
16978
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2702 unwind_protect
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2703 rand ("state", svec);
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2704 A = rand (varargin{:});
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2705 unwind_protect_cleanup
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2706 rand ("state", randstate);
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2707 end_unwind_protect
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2708
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2709 endfunction
00379f9f8773 gallery.m: Add 'uniformdata' matrix to function.
Rik <rik@octave.org>
parents: 16933
diff changeset
2710
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2711 function A = wathen (nx, ny, k = 0)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2712
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2713 ## WATHEN returns the Wathen matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2714 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2715 ## Discussion:
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2716 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2717 ## The Wathen matrix is a finite element matrix which is sparse.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2718 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2719 ## The entries of the matrix depend in part on a physical quantity
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2720 ## related to density. That density is here assigned random values between
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2721 ## 0 and 100.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2722 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2723 ## A = WATHEN ( NX, NY ) is a sparse random N-by-N finite element matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2724 ## where N = 3*NX*NY + 2*NX + 2*NY + 1.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2725 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2726 ## A is the consistent mass matrix for a regular NX-by-NY
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2727 ## grid of 8-node (serendipity) elements in 2 space dimensions.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2728 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2729 ## Here is an illustration for NX = 3, NX = 2:
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2730 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2731 ## 23-24-25-26-27-28-29
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2732 ## | | | |
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2733 ## 19 20 21 22
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2734 ## | | | |
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2735 ## 12-13-14-15-16-17-18
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2736 ## | | | |
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2737 ## 8 9 10 11
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2738 ## | | | |
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2739 ## 1--2--3--4--5--6--7
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2740 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2741 ## For this example, the total number of nodes is, as expected,
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2742 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2743 ## N = 3 * 3 * 2 + 2 * 2 + 2 * 3 + 1 = 29.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2744 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2745 ## A is symmetric positive definite for any (positive) values of
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2746 ## the density, RHO(NX,NY), which is chosen randomly in this routine.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2747 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2748 ## In particular, if D = DIAG(DIAG(A)), then
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2749 ## 0.25 <= EIG(INV(D)*A) <= 4.5
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2750 ## for any positive integers NX and NY and any densities RHO(NX,NY).
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2751 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2752 ## A = WATHEN ( NX, NY, 1 ) returns the diagonally scaled matrix.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2753 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2754 ## Modified:
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2755 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2756 ## 17 September 2007
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2757 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2758 ## Author:
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2759 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2760 ## Nicholas Higham
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2761 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2762 ## Reference:
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2763 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2764 ## Nicholas Higham,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2765 ## Algorithm 694: A Collection of Test Matrices in MATLAB,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2766 ## ACM Transactions on Mathematical Software,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2767 ## Volume 17, Number 3, September 1991, pages 289-305.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2768 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2769 ## Andrew Wathen,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2770 ## Realistic eigenvalue bounds for the Galerkin mass matrix,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2771 ## IMA Journal of Numerical Analysis,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2772 ## Volume 7, 1987, pages 449-457.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2773 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2774 ## Parameters:
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2775 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2776 ## Input, integer NX, NY, the number of elements in the X and Y directions
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2777 ## of the finite element grid. NX and NY must each be at least 1.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2778 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2779 ## Optional input, integer K, is used to request that the diagonally scaled
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2780 ## version of the matrix be returned. This happens if K is specified with
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2781 ## the value 1.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2782 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2783 ## Output, sparse real A(N,N), the matrix. The dimension N is determined by
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2784 ## NX and NY, as described above. A is stored in the MATLAB sparse matrix
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2785 ## format.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2786
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2787 if (nargin < 2 || nargin > 3)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2788 error ("gallery: 2 or 3 arguments are required for wathen matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2789 elseif (! isnumeric (nx) || ! isscalar (nx) || nx < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2790 error ("gallery: NX must be a positive scalar for wathen matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2791 elseif (! isnumeric (ny) || ! isscalar (ny) || ny < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2792 error ("gallery: NY must be a positive scalar for wathen matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2793 elseif (! isscalar (k))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2794 error ("gallery: K must be a scalar for wathen matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2795 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2796
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2797 e1 = [ 6 -6 2 -8
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2798 -6 32 -6 20
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2799 2 -6 6 -6
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2800 -8 20 -6 32 ];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2801
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2802 e2 = [ 3 -8 2 -6
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2803 -8 16 -8 20
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2804 2 -8 3 -8
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2805 -6 20 -8 16 ];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2806
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2807 e = [ e1 e2
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2808 e2' e1] / 45;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2809
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2810 n = 3*nx*ny + 2*nx + 2*ny + 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2811
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2812 A = sparse (n, n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2813
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2814 rho = 100 * rand (nx, ny);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2815
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2816 for j = 1:ny
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2817 for i = 1:nx
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2818 ##
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2819 ## For the element (I,J), determine the indices of the 8 nodes.
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2820 ##
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2821 nn(1) = 3*j*nx + 2*i + 2*j + 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2822 nn(2) = nn(1) - 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2823 nn(3) = nn(2) - 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2824 nn(4) = (3*j - 1) * nx + 2*j + i - 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2825 nn(5) = 3 * (j-1) * nx + 2*i + 2*j - 3;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2826 nn(6) = nn(5) + 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2827 nn(7) = nn(6) + 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2828 nn(8) = nn(4) + 1;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2829
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2830 em = e * rho(i,j);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2831
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2832 for krow = 1:8
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2833 for kcol = 1:8
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2834 A(nn(krow),nn(kcol)) = A(nn(krow),nn(kcol)) + em(krow,kcol);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2835 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2836 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2837
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2838 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2839 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2840
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2841 ## If requested, return A with diagonal scaling.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2842 if (k)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2843 A = diag (diag (A)) \ A;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2844 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2845
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2846 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2847
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2848 function [A, b] = wilk (n)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2849
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2850 ## WILK Various specific matrices devised/discussed by Wilkinson.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2851 ## [A, b] = WILK(N) is the matrix or system of order N.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2852 ## N = 3: upper triangular system Ux=b illustrating inaccurate solution.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2853 ## N = 4: lower triangular system Lx=b, ill-conditioned.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2854 ## N = 5: HILB(6)(1:5,2:6)*1.8144. Symmetric positive definite.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2855 ## N = 21: W21+, tridiagonal. Eigenvalue problem.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2856 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2857 ## References:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2858 ## J.H. Wilkinson, Error analysis of direct methods of matrix inversion,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2859 ## J. Assoc. Comput. Mach., 8 (1961), pp. 281-330.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2860 ## J.H. Wilkinson, Rounding Errors in Algebraic Processes, Notes on Applied
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2861 ## Science No. 32, Her Majesty's Stationery Office, London, 1963.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2862 ## J.H. Wilkinson, The Algebraic Eigenvalue Problem, Oxford University
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2863 ## Press, 1965.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2864
28891
de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input.
Rik <rik@octave.org>
parents: 27931
diff changeset
2865 if (nargin < 1)
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2866 error ("gallery: 1 argument is required for wilk matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2867 elseif (! isnumeric (n) || ! isscalar (n))
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2868 error ("gallery: N must be a numeric scalar for wilk matrix");
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2869 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2870
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2871 if (n == 3)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2872 ## Wilkinson (1961) p.323.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2873 A = [ 1e-10 0.9 -0.4
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2874 0 0.9 -0.4
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2875 0 0 1e-10 ];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2876
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2877 b = [ 0
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2878 0
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2879 1];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2880
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2881 elseif (n == 4)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2882 ## Wilkinson (1963) p.105.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2883 A = [0.9143e-4 0 0 0
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2884 0.8762 0.7156e-4 0 0
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2885 0.7943 0.8143 0.9504e-4 0
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2886 0.8017 0.6123 0.7165 0.7123e-4];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2887
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2888 b = [0.6524
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2889 0.3127
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2890 0.4186
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2891 0.7853];
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2892
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2893 elseif (n == 5)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2894 ## Wilkinson (1965), p.234.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2895 A = hilb (6);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2896 A = A(1:5, 2:6) * 1.8144;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2897
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2898 elseif (n == 21)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2899 ## Wilkinson (1965), p.308.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2900 E = diag (ones (n-1, 1), 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2901 m = (n-1)/2;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2902 A = diag (abs (-m:m)) + E + E';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2903
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2904 else
28905
89a425f2c202 maint: Use Octave convention that error() messages don't end with a period.
Rik <rik@octave.org>
parents: 28904
diff changeset
2905 error ("gallery: unknown N '%d' for wilk matrix", n);
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2906 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2907
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2908 endfunction
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2909
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2910 ## NOTE: bandred is part of the Test Matrix Toolbox and is used by randsvd()
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2911 function A = bandred (A, kl, ku)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2912
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2913 ## BANDRED Band reduction by two-sided unitary transformations.
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2914 ## B = BANDRED(A, KL, KU) is a matrix unitarily equivalent to A
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2915 ## with lower bandwidth KL and upper bandwidth KU
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2916 ## (i.e. B(i,j) = 0 if i > j+KL or j > i+KU).
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2917 ## The reduction is performed using Householder transformations.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2918 ## If KU is omitted it defaults to KL.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2919 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2920 ## Called by RANDSVD.
27216
823b4bcf79fc unless necessary for formatting or code, use ' instead of `
John W. Eaton <jwe@octave.org>
parents: 27085
diff changeset
2921 ## This is a 'standard' reduction. Cf. reduction to bidiagonal form
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2922 ## prior to computing the SVD. This code is a little wasteful in that
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2923 ## it computes certain elements which are immediately set to zero!
19593
446c46af4b42 strip trailing whitespace from most source files
John W. Eaton <jwe@octave.org>
parents: 17386
diff changeset
2924 ##
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2925 ## Reference:
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2926 ## G.H. Golub and C.F. Van Loan, Matrix Computations, second edition,
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2927 ## Johns Hopkins University Press, Baltimore, Maryland, 1989.
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
2928 ## Section 5.4.3.
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2929
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2930 ## Check for special case where order of left/right transformations matters.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2931 ## Easiest approach is to work on the transpose, flipping back at the end.
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2932 flip = false;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2933 if (ku == 0)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2934 flip = true;
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2935 A = A';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2936 [ku, kl] = deal (kl, ku);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2937 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2938
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2939 [m, n] = size (A);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2940
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2941 for j = 1:min (min (m, n), max (m-kl-1, n-ku-1))
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2942 if (j+kl+1 <= m)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2943 [v, beta] = house (A(j+kl:m,j));
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2944 temp = A(j+kl:m,j:n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2945 A(j+kl:m,j:n) = temp - beta*v*(v'*temp);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2946 A(j+kl+1:m,j) = zeros (m-j-kl, 1);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2947 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2948
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2949 if (j+ku+1 <= n)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2950 [v, beta] = house (A(j,j+ku:n)');
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2951 temp = A(j:m,j+ku:n);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2952 A(j:m,j+ku:n) = temp - beta*(temp*v)*v';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2953 A(j,j+ku+1:n) = zeros (1, n-j-ku);
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2954 endif
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2955 endfor
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2956
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2957 if (flip)
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2958 A = A';
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2959 endif
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2960
16634
2510fffc05e1 gallery: new function
Carnë Draug <carandraug@octave.org>
parents:
diff changeset
2961 endfunction
17338
1c89599167a6 maint: End m-files with 1 blank line.
Rik <rik@octave.org>
parents: 17312
diff changeset
2962
20296
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2963 ## NOTE: qmult is part of the Test Matrix Toolbox and is used by randsvd()
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2964 function B = qmult (A)
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
2965
20296
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2966 ## QMULT Pre-multiply by random orthogonal matrix.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2967 ## QMULT(A) is Q*A where Q is a random real orthogonal matrix from
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2968 ## the Haar distribution, of dimension the number of rows in A.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2969 ## Special case: if A is a scalar then QMULT(A) is the same as
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2970 ## QMULT(EYE(A)).
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2971 ##
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2972 ## Called by RANDSVD.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2973 ##
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2974 ## Reference:
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2975 ## G.W. Stewart, The efficient generation of random
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2976 ## orthogonal matrices with an application to condition estimators,
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2977 ## SIAM J. Numer. Anal., 17 (1980), 403-409.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2978
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2979 [n, m] = size (A);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2980
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2981 ## Handle scalar A
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2982 if (isscalar (A))
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2983 n = A;
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2984 A = eye (n);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2985 endif
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2986
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2987 d = zeros (n);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2988
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2989 for k = n-1:-1:1
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2990 ## Generate random Householder transformation.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2991 x = randn (n-k+1, 1);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2992 s = norm (x);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2993 sgn = sign (x(1)) + (x(1) == 0); # Modification for sign(1)=1.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2994 s = sgn*s;
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2995 d(k) = -sgn;
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2996 x(1) = x(1) + s;
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2997 beta = s*x(1);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2998
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
2999 ## Apply the transformation to A.
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3000 y = x'*A(k:n,:);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3001 A(k:n,:) = A(k:n,:) - x*(y/beta);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3002 endfor
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3003
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3004 ## Tidy up signs
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3005 for i = 1:n-1
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3006 A(i,:) = d(i)*A(i,:);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3007 endfor
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3008 A(n,:) = A(n,:) * sign (randn);
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3009 B = A;
30379
363fb10055df maint: Style check m-files ahead of 7.1 release.
Rik <rik@octave.org>
parents: 30330
diff changeset
3010
20296
0b9d23557506 gallery: fix randsvd by adding missing dependency qmult().
Carnë Draug <carandraug@octave.org>
parents: 20295
diff changeset
3011 endfunction
19226
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3012
21759
b002b4331a12 maint: Use two newlines after endfunction and start of BIST tests.
Rik <rik@octave.org>
parents: 21751
diff changeset
3013
19226
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3014 ## BIST testing for just a few functions to verify that the main gallery
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3015 ## dispatch function works.
20929
45a64a6c7273 fix comment character style in most .m files to be consistent
John W. Eaton <jwe@octave.org>
parents: 20852
diff changeset
3016 %!assert (gallery ("clement", 3), [0 1 0; 2 0 2; 0 1 0])
45a64a6c7273 fix comment character style in most .m files to be consistent
John W. Eaton <jwe@octave.org>
parents: 20852
diff changeset
3017 %!assert (gallery ("invhess", 2), [1 -1; 1 2])
19226
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3018
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3019 ## Test input validation of main dispatch function only
28896
90fea9cc9caa test: Add expected error message <Invalid call> to BIST tests for nargin.
Rik <rik@octave.org>
parents: 28891
diff changeset
3020 %!error <Invalid call> gallery ()
19226
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3021 %!error <NAME must be a string> gallery (123)
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3022 %!error <matrix binomial not implemented> gallery ("binomial")
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3023 %!error <unknown matrix with NAME foobar> gallery ("foobar")
cdfc8bc9ab62 gallery.m: Add BIST tests for central dispatch function.
Rik <rik@octave.org>
parents: 19040
diff changeset
3024
21759
b002b4331a12 maint: Use two newlines after endfunction and start of BIST tests.
Rik <rik@octave.org>
parents: 21751
diff changeset
3025 ## BIST testing for individual gallery functions
19944
941e782d0429 gallery: performance increase for minij matrix.
Carnë Draug <carandraug@octave.org>
parents: 19833
diff changeset
3026 %!assert (gallery ("minij", 4), [1 1 1 1; 1 2 2 2; 1 2 3 3; 1 2 3 4])
941e782d0429 gallery: performance increase for minij matrix.
Carnë Draug <carandraug@octave.org>
parents: 19833
diff changeset
3027 %!assert (gallery ("minij", 1), 1)
941e782d0429 gallery: performance increase for minij matrix.
Carnë Draug <carandraug@octave.org>
parents: 19833
diff changeset
3028 %!assert (gallery ("minij", 0), [])
941e782d0429 gallery: performance increase for minij matrix.
Carnë Draug <carandraug@octave.org>
parents: 19833
diff changeset
3029 %!assert (gallery ("minij", -1), [])
20299
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3030
23381
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3031 %!test
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3032 %! exp = 1 ./ [
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3033 %! 2 3 4 5 6
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3034 %! 3 4 5 6 7
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3035 %! 4 5 6 7 8
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3036 %! 5 6 7 8 9
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3037 %! 6 7 8 9 10];
28929
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3038 %! assert (gallery ("cauchy", 5), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3039 %! assert (gallery ("cauchy", 1:5), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3040 %! assert (gallery ("cauchy", 1:5, 1:5), exp);
23381
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3041 %!
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3042 %! exp = 1 ./ [
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3043 %! 1 2 3 4 5
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3044 %! 2 3 4 5 6
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3045 %! 3 4 5 6 7
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3046 %! 4 5 6 7 8
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3047 %! 5 6 7 8 9];
28929
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3048 %! assert (gallery ("cauchy", 0:4, 1:5), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3049 %! assert (gallery ("cauchy", 1:5, 0:4), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3050 %! assert (gallery ("cauchy", 1:5, 4:-1:0), fliplr (exp));
23381
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3051 %!
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3052 %! exp = 1 ./ [
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3053 %! -1 0 1 2 3
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3054 %! 0 1 2 3 4
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3055 %! 1 2 3 4 5
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3056 %! 2 3 4 5 6
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3057 %! 3 4 5 6 7];
28929
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3058 %! assert (gallery ("cauchy", 1:5, -2:2), exp);
23381
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3059 %!
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3060 %! exp = 1 ./ [
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3061 %! 8 18 -4 2
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3062 %! 13 23 1 7
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3063 %! 9 19 -3 3
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3064 %! 15 25 3 9];
28929
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3065 %! assert (gallery ("cauchy", [-2 3 -1 5], [10 20 -2 4]), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3066 %! assert (gallery ("cauchy", [-2 3 -1 5], [10 20 -2 4]'), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3067 %! assert (gallery ("cauchy", [-2 3 -1 5]', [10 20 -2 4]), exp);
20299
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3068
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3069 %!assert (size (gallery ("chebspec", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3070 %!assert (size (gallery ("chebspec", 5, 1)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3071 %!assert (size (gallery ("chebspec", 5, 0)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3072
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3073 %!assert (size (gallery ("chebvand", 7)), [7 7])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3074 %!assert (size (gallery ("chebvand", 1:7)), [7 7])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3075 %!assert (size (gallery ("chebvand", 5, 7)), [5 7])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3076
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3077 %!assert (size (gallery ("chow", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3078 %!assert (size (gallery ("chow", 5, 6)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3079 %!assert (size (gallery ("chow", 5, 6, 7)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3080
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3081 %!assert (gallery ("circul", 3), [1 2 3; 3 1 2; 2 3 1])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3082 %!assert (gallery ("circul", [1 3 6]), [1 3 6; 6 1 3; 3 6 1])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3083
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3084 %!assert (size (gallery ("clement", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3085 %!assert (size (gallery ("clement", 5, 1)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3086 %!assert (size (gallery ("clement", 5, 0)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3087
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3088 %!assert (size (gallery ("compar", ones (5))), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3089 %!assert (size (gallery ("compar", ones (5), 0)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3090 %!assert (size (gallery ("compar", ones (5), 1)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3091
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3092 %!assert (size (gallery ("condex", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3093 %!assert (size (gallery ("condex", 4, 1)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3094 %!assert (size (gallery ("condex", 4, 1, 50)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3095
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3096 %!assert (size (gallery ("cycol", [4 5])), [4 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3097 %!assert (size (gallery ("cycol", [4 5], 1)), [4 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3098 %!assert (size (gallery ("cycol", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3099 %!assert (size (gallery ("cycol", 4, 1)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3100
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3101 %!assert (size (gallery ("dorr", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3102 %!assert (cellfun (@rows, nthargout (1:3, @gallery, "dorr", 4)), [3 4 3])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3103
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3104 %!assert (size (gallery ("dramadah", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3105 %!assert (size (gallery ("dramadah", 5, 2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3106
23381
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3107 %!test
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3108 %! exp = [
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3109 %! 0 1 2 3 4
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3110 %! 1 0 1 2 3
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3111 %! 2 1 0 1 2
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3112 %! 3 2 1 0 1
e15ffa2b2262 gallery: use broadcasting to generate cauchy and fiedler matrices
Carnë Draug <carandraug@octave.org>
parents: 23084
diff changeset
3113 %! 4 3 2 1 0];
28929
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3114 %! assert (gallery ("fiedler", 5), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3115 %! assert (gallery ("fiedler", 1:5), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3116 %! assert (gallery ("fiedler", -2:2), exp);
9e43deb9bfc3 maint: Use semicolon after assert statement inside %!test blocks.
Rik <rik@octave.org>
parents: 28905
diff changeset
3117 %! assert (gallery ("fiedler", 2:5), exp(1:4,1:4));
20299
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3118
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3119 %!assert (size (gallery ("forsythe", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3120 %!assert (size (gallery ("forsythe", 5, 1, 0.5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3121 %!assert (size (gallery ("forsythe", 5, 4, 7)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3122
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3123 %!assert (size (gallery ("frank", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3124 %!assert (size (gallery ("frank", 5, 1)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3125
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3126 %!assert (size (gallery ("gcdmat", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3127
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3128 %!assert (size (gallery ("gearmat", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3129 %!assert (size (gallery ("gearmat", 5, 4)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3130 %!assert (size (gallery ("gearmat", 5, 4, 3)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3131
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3132 %!assert (size (gallery ("grcar", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3133 %!assert (size (gallery ("grcar", 5, 2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3134
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3135 %!error <N must be even> gallery ("hanowa", 5)
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3136 %!assert (size (gallery ("hanowa", 6, 5)), [6 6])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3137 %!assert (size (gallery ("hanowa", 6, 5)), [6 6])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3138
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3139 %!assert (size (gallery ("house", [1:5]')), [5 1])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3140 %!assert (cellfun (@rows, nthargout (1:2, @gallery, "house", [1:5]')), [5 1])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3141
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3142 %!assert (size (gallery ("integerdata", 5, [3 2], 5)), [3 2])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3143 %!assert (size (gallery ("integerdata", 5, [3 2 6], 5)), [3 2 6])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3144
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3145 %!assert (size (gallery ("invhess", 1:4, 1:3)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3146
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3147 %!assert (size (gallery ("invol", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3148
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3149 %!assert (size (gallery ("ipjfact", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3150 %!assert (size (gallery ("ipjfact", 4, 0)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3151 %!assert (size (gallery ("ipjfact", 4, 1)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3152
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3153 %!assert (size (gallery ("jordbloc", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3154 %!assert (size (gallery ("jordbloc", 4, 1)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3155 %!assert (size (gallery ("jordbloc", 4, 3)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3156
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3157 %!assert (size (gallery ("kahan", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3158 %!assert (size (gallery ("kahan", [4 5])), [4 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3159 %!assert (size (gallery ("kahan", [4 5], 1)), [4 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3160 %!assert (size (gallery ("kahan", [4 5], 1, 30)), [4 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3161
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3162 %!assert (size (gallery ("kms", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3163 %!assert (size (gallery ("kms", 5, 0.2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3164
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3165 %!assert (size (gallery ("krylov", 4)), [4 4])
22021
e67ff2b11147 Check that second argument to size () is a scalar (bug #48368).
Lachlan Andrew <lachlanbis@gmail.com>
parents: 21759
diff changeset
3166 %!assert (size (gallery ("krylov", ones (4))), [4 4])
e67ff2b11147 Check that second argument to size () is a scalar (bug #48368).
Lachlan Andrew <lachlanbis@gmail.com>
parents: 21759
diff changeset
3167 %!assert (size (gallery ("krylov", ones (4), [.2 .3 .4 .5], 3)), [4 3])
20299
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3168
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3169 %!assert (size (gallery ("lauchli", 5)), [6 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3170 %!assert (size (gallery ("lauchli", 5, 3)), [6 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3171
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3172 %!assert (size (gallery ("lehmer", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3173
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3174 %!assert (size (gallery ("lesp", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3175
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3176 %!assert (size (gallery ("lotkin", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3177
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3178 %!assert (size (gallery ("minij", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3179
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3180 %!assert (size (gallery ("moler", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3181 %!assert (size (gallery ("moler", 5, 0.2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3182
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3183 %!assert (size (gallery ("neumann", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3184
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3185 %!assert (size (gallery ("normaldata", [5 4 6], 3)), [5 4 6])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3186
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3187 %!assert (size (gallery ("orthog", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3188 %!assert (size (gallery ("orthog", 5, 2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3189 %!assert (size (gallery ("orthog", 5, -2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3190
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3191 %!assert (size (gallery ("parter", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3192
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3193 %!assert (size (gallery ("pei", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3194 %!assert (size (gallery ("pei", 5, 4)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3195
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3196 %!assert (size (gallery ("poisson", 1)), [1 1])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3197 %!assert (size (gallery ("poisson", 4)), [16 16])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3198 %!assert (size (gallery ("poisson", 5)), [25 25])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3199
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3200 %!assert (size (gallery ("prolate", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3201 %!assert (size (gallery ("prolate", 5, 0.5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3202
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3203 %!assert (size (gallery ("randhess", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3204 %!assert (size (gallery ("randhess", 2:5)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3205
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3206 %!assert (size (gallery ("rando", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3207 %!assert (size (gallery ("rando", 5, 2)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3208
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3209 %!assert (size (gallery ("randsvd", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3210 %!assert (size (gallery ("randsvd", [5 3])), [5 3])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3211
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3212 %!assert (size (gallery ("redheff", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3213 %!assert (size (gallery ("riemann", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3214 %!assert (size (gallery ("ris", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3215
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3216 %!assert (size (gallery ("smoke", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3217 %!assert (size (gallery ("smoke", 5, 1)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3218 %!assert (gallery ("smoke", 5, 1)(5, 1), 0)
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3219
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3220 %!assert (size (gallery ("toeppd", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3221
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3222 %!assert (size (gallery ("toeppen", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3223
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3224 %!assert (size (gallery ("tridiag", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3225 %!assert (size (gallery ("tridiag", 1:4, 1:5, 1:4)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3226 %!assert (gallery ("tridiag", 5), gallery ("tridiag", 5, -1, 2, -1))
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3227
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3228 %!assert (size (gallery ("triw", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3229
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3230 %!assert (size (gallery ("uniformdata", [5 3 4], 3)), [5 3 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3231
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3232 %!assert (size (gallery ("wathen", 2, 3)), [29 29])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3233
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3234 %!assert (cellfun (@rows, nthargout (1:2, @gallery, "wilk", 3)), [3 3])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3235 %!assert (cellfun (@rows, nthargout (1:2, @gallery, "wilk", 4)), [4 4])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3236 %!assert (size (gallery ("wilk", 5)), [5 5])
c5a8eff5a05d gallery: add very basic tests (check output size) for all matrix types.
Carnë Draug <carandraug@octave.org>
parents: 20298
diff changeset
3237 %!assert (size (gallery ("wilk", 21)), [21 21])