annotate scripts/linear-algebra/logm.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 a40c0b7aa376
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: 30383
diff changeset
3 ## Copyright (C) 2008-2022 The Octave Project Developers
27918
b442ec6dda5c use centralized file for copyright info for individual contributors
John W. Eaton <jwe@octave.org>
parents: 26376
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/>.
4334
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
7 ##
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
8 ## This file is part of Octave.
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
9 ##
24534
194eb4bd202b maint: Update punctuation for GPL v3 license text.
Rik <rik@octave.org>
parents: 23220
diff changeset
10 ## Octave is free software: you can redistribute it and/or modify it
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
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: 23220
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.
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
14 ##
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
15 ## Octave is distributed in the hope that it will be useful, but
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
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.
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
19 ##
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
20 ## You should have received a copy of the GNU General Public License
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
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: 23220
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 ########################################################################
4334
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
25
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
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: 20231
diff changeset
27 ## @deftypefn {} {@var{s} =} logm (@var{A})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20231
diff changeset
28 ## @deftypefnx {} {@var{s} =} logm (@var{A}, @var{opt_iters})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files.
Rik <rik@octave.org>
parents: 20231
diff changeset
29 ## @deftypefnx {} {[@var{s}, @var{iters}] =} logm (@dots{})
20160
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
30 ## Compute the matrix logarithm of the square matrix @var{A}.
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
31 ##
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
32 ## The implementation utilizes a Pad@'e approximant and the identity
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
33 ##
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
34 ## @example
14327
4d917a6a858b doc: Use Octave coding conventions in @example blocks of docstrings.
Rik <octave@nomad.inbox5.com>
parents: 14138
diff changeset
35 ## logm (@var{A}) = 2^k * logm (@var{A}^(1 / 2^k))
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
36 ## @end example
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
37 ##
20160
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
38 ## The optional input @var{opt_iters} is the maximum number of square roots
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
39 ## to compute and defaults to 100.
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
40 ##
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
41 ## The optional output @var{iters} is the number of square roots actually
03b9d17a2d95 doc: Update more docstrings to have one sentence summary as first line.
Rik <rik@octave.org>
parents: 19833
diff changeset
42 ## computed.
12584
7ef7e20057fa Improve documentation strings in Linear Algebra chapter.
Rik <octave@nomad.inbox5.com>
parents: 11587
diff changeset
43 ## @seealso{expm, sqrtm}
4334
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
44 ## @end deftypefn
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
45
11587
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
46 ## Reference: N. J. Higham, Functions of Matrices: Theory and Computation
11033
d9c8916bb9dd Untabify a few remaining .m scripts.
Rik <octave@nomad.inbox5.com>
parents: 10827
diff changeset
47 ## (SIAM, 2008.)
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
48 ##
4334
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
49
16768
e2de3c8882be copyright notice fixes
John W. Eaton <jwe@octave.org>
parents: 14868
diff changeset
50 ## Author: N. J. Higham
e2de3c8882be copyright notice fixes
John W. Eaton <jwe@octave.org>
parents: 14868
diff changeset
51 ## Author: Richard T. Guy <guyrt7@wfu.edu>
27985
9f9ac219896d maint: Remove remaining "Author:" instances from code base.
Rik <rik@octave.org>
parents: 27978
diff changeset
52
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
53 function [s, iters] = logm (A, opt_iters = 100)
11587
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
54
28789
28de41192f3c Eliminate unneeded verification of nargin, nargout in m-files.
Rik <rik@octave.org>
parents: 27985
diff changeset
55 if (nargin == 0)
6046
34f96dd5441b [project @ 2006-10-10 16:10:25 by jwe]
jwe
parents: 5307
diff changeset
56 print_usage ();
4334
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
57 endif
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
58
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
59 if (! issquare (A))
11472
1740012184f9 Use uppercase for variable names in error() strings to match Info documentation. Only m-files done.
Rik <octave@nomad.inbox5.com>
parents: 11471
diff changeset
60 error ("logm: A must be a square matrix");
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
61 endif
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
62
11476
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
63 if (isscalar (A))
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
64 s = log (A);
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
65 return;
29770
4778b21b1386 expm.m, logm.m: Use function "isdiag" to detect if input is a diagonal matrix (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29769
diff changeset
66 elseif (isdiag (A))
11476
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
67 s = diag (log (diag (A)));
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
68 return;
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
69 endif
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
70
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
71 [u, s] = schur (A);
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
72
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
73 if (isreal (A))
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
74 [u, s] = rsf2csf (u, s);
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
75 endif
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
76
13097
52e4aa30d5b2 logm.m: Return real matrix when all eigenvalues are real (Bug #32121).
Rik <octave@nomad.inbox5.com>
parents: 12584
diff changeset
77 eigv = diag (s);
30383
8afdeac24ba4 maint: Use space after function name and before opening parenthesis.
Rik <rik@octave.org>
parents: 29806
diff changeset
78 n = rows (A);
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
79 tol = n * eps (max (abs (eigv)));
29769
fe06c183cc4e logm.m: Allow tolerance in check for real negative values in complex vector (bug #60738).
Steven <steven.waldrip@gmail.com>
parents: 29738
diff changeset
80 real_neg_eigv = (real (eigv) < -tol) & (imag (eigv) <= tol);
29738
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
81 if (any (real_neg_eigv))
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
82 warning ("Octave:logm:non-principal",
11458
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
83 "logm: principal matrix logarithm is not defined for matrices with negative eigenvalues; computing non-principal logarithm");
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
84 endif
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
85
29738
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
86 real_eig = ! any (real_neg_eigv);
13097
52e4aa30d5b2 logm.m: Return real matrix when all eigenvalues are real (Bug #32121).
Rik <octave@nomad.inbox5.com>
parents: 12584
diff changeset
87
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
88 if (max (abs (triu (s,1))(:)) < tol)
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
89 ## Will run for Hermitian matrices as Schur decomposition is diagonal.
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
90 ## This way is faster and more accurate but only works on a diagonal matrix.
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
91 logeigv = log (eigv);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
92 logeigv(isinf (logeigv)) = -log (realmax ());
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
93 s = u * diag (logeigv) * u';
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
94 iters = 0;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
95 else
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
96 k = 0;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
97 ## Algorithm 11.9 in "Function of matrices", by N. Higham
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
98 theta = [0, 0, 1.61e-2, 5.38e-2, 1.13e-1, 1.86e-1, 2.6429608311114350e-1];
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
99 p = 0;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
100 m = 7;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
101 while (k < opt_iters)
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
102 tau = norm (s - eye (n), 1);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
103 if (tau <= theta (7))
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
104 p += 1;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
105 j(1) = find (tau <= theta, 1);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
106 j(2) = find (tau / 2 <= theta, 1);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
107 if (j(1) - j(2) <= 1 || p == 2)
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
108 m = j(1);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
109 break;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
110 endif
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
111 endif
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
112 k += 1;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
113 s = sqrtm (s);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
114 endwhile
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
115
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
116 if (k >= opt_iters)
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
117 warning ("logm: maximum number of square roots exceeded; results may still be accurate");
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
118 endif
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
119
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
120 s -= eye (n);
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
121
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
122 if (m > 1)
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
123 s = logm_pade_pf (s, m);
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
124 endif
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
125
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
126 s = 2^k * u * s * u';
11476
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
127
29778
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
128 if (nargout == 2)
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
129 iters = k;
c44e54bb018b logm.m: Improve performance and accuracy for Hermitian input (bug #60738).
Steven Waldrip <steven.waldrip@gmail.com>
parents: 29771
diff changeset
130 endif
11476
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
131 endif
13097
52e4aa30d5b2 logm.m: Return real matrix when all eigenvalues are real (Bug #32121).
Rik <octave@nomad.inbox5.com>
parents: 12584
diff changeset
132 ## Remove small complex values (O(eps)) which may have entered calculation
14868
5d3a684236b0 maint: Use Octave coding conventions for cuddling parentheses in scripts directory
Rik <octave@nomad.inbox5.com>
parents: 14491
diff changeset
133 if (real_eig && isreal (A))
13097
52e4aa30d5b2 logm.m: Return real matrix when all eigenvalues are real (Bug #32121).
Rik <octave@nomad.inbox5.com>
parents: 12584
diff changeset
134 s = real (s);
52e4aa30d5b2 logm.m: Return real matrix when all eigenvalues are real (Bug #32121).
Rik <octave@nomad.inbox5.com>
parents: 12584
diff changeset
135 endif
52e4aa30d5b2 logm.m: Return real matrix when all eigenvalues are real (Bug #32121).
Rik <octave@nomad.inbox5.com>
parents: 12584
diff changeset
136
4334
764229f9a5c8 [project @ 2003-02-19 06:24:02 by jwe]
jwe
parents:
diff changeset
137 endfunction
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
138
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
139 ################## ANCILLARY FUNCTIONS ################################
11033
d9c8916bb9dd Untabify a few remaining .m scripts.
Rik <octave@nomad.inbox5.com>
parents: 10827
diff changeset
140 ###### Taken from the mfttoolbox (GPL 3) by D. Higham.
11587
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
141 ###### Reference:
c792872f8942 all script files: untabify and strip trailing whitespace
John W. Eaton <jwe@octave.org>
parents: 11523
diff changeset
142 ###### D. Higham, Functions of Matrices: Theory and Computation
11033
d9c8916bb9dd Untabify a few remaining .m scripts.
Rik <octave@nomad.inbox5.com>
parents: 10827
diff changeset
143 ###### (SIAM, 2008.).
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
144 #######################################################################
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
145
31253
a40c0b7aa376 maint: changes to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 30564
diff changeset
146 ## LOGM_PADE_PF Evaluate Pade approximant to matrix log by partial fractions.
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
147 ## Y = LOGM_PADE_PF(A,M) evaluates the [M/M] Pade approximation to
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
148 ## LOG(EYE(SIZE(A))+A) using a partial fraction expansion.
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
149
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
150 function s = logm_pade_pf (A, m)
21758
ffad2baa90f7 maint: Use newlines to make code more readable.
Rik <rik@octave.org>
parents: 20852
diff changeset
151
11458
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
152 [nodes, wts] = gauss_legendre (m);
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
153 ## Convert from [-1,1] to [0,1].
11458
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
154 nodes = (nodes+1)/2;
20231
83792dd9bcc1 Use in-place operators in m-files where possible.
Rik <rik@octave.org>
parents: 20160
diff changeset
155 wts /= 2;
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
156
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
157 n = length (A);
11458
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
158 s = zeros (n);
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
159 for j = 1:m
11471
994e2a93a8e2 Use uppercase 'A' to refer to matrix inputs in m-files.
Rik <octave@nomad.inbox5.com>
parents: 11465
diff changeset
160 s += wts(j)*(A/(eye (n) + nodes(j)*A));
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
161 endfor
21758
ffad2baa90f7 maint: Use newlines to make code more readable.
Rik <rik@octave.org>
parents: 20852
diff changeset
162
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
163 endfunction
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
164
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
165 ######################################################################
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
166 ## GAUSS_LEGENDRE Nodes and weights for Gauss-Legendre quadrature.
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
167 ## [X,W] = GAUSS_LEGENDRE(N) computes the nodes X and weights W
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
168 ## for N-point Gauss-Legendre quadrature.
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
169
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
170 ## Reference:
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
171 ## G. H. Golub and J. H. Welsch, Calculation of Gauss quadrature
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
172 ## rules, Math. Comp., 23(106):221-230, 1969.
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
173
11458
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
174 function [x, w] = gauss_legendre (n)
21758
ffad2baa90f7 maint: Use newlines to make code more readable.
Rik <rik@octave.org>
parents: 20852
diff changeset
175
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
176 i = 1:n-1;
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
177 v = i./sqrt ((2*i).^2-1);
11458
93a039fe681e logm: style fixes
John W. Eaton <jwe@octave.org>
parents: 11033
diff changeset
178 [V, D] = eig (diag (v, -1) + diag (v, 1));
10827
228cd18455a6 logm.m: Improve documentation string. Add GPL header. Add additional test block.
Rik <octave@nomad.inbox5.com>
parents: 10825
diff changeset
179 x = diag (D);
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
180 w = 2*(V(1,:)'.^2);
21758
ffad2baa90f7 maint: Use newlines to make code more readable.
Rik <rik@octave.org>
parents: 20852
diff changeset
181
10825
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
182 endfunction
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
183
cace99cb01ab rewrite logm (M. Caliari, R.T. Guy)
Jaroslav Hajek <highegg@gmail.com>
parents: 7017
diff changeset
184
14363
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14327
diff changeset
185 %!assert (norm (logm ([1 -1;0 1]) - [0 -1; 0 0]) < 1e-5)
19670
e5facc6eec13 Silence warning messages in %!test code.
Rik <rik@octave.org>
parents: 17744
diff changeset
186 %!test
e5facc6eec13 Silence warning messages in %!test code.
Rik <rik@octave.org>
parents: 17744
diff changeset
187 %! warning ("off", "Octave:logm:non-principal", "local");
e5facc6eec13 Silence warning messages in %!test code.
Rik <rik@octave.org>
parents: 17744
diff changeset
188 %! assert (norm (expm (logm ([-1 2 ; 4 -1])) - [-1 2 ; 4 -1]) < 1e-5);
14363
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14327
diff changeset
189 %!assert (logm ([1 -1 -1;0 1 -1; 0 0 1]), [0 -1 -1.5; 0 0 -1; 0 0 0], 1e-5)
11476
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
190 %!assert (logm (10), log (10))
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
191 %!assert (full (logm (eye (3))), logm (full (eye (3))))
ff7e0776ba0f logm.m: handle scalar and diagonal matrix arguments specially; call log_pade_pf only if m > 1
John W. Eaton <jwe@octave.org>
parents: 11472
diff changeset
192 %!assert (full (logm (10*eye (3))), logm (full (10*eye (3))), 8*eps)
14481
d2bffa78730e Fix logm for complex matrix with real eigenvalues (bug #34893).
Marco Caliari <marco.caliari@univr.it>
parents: 14327
diff changeset
193 %!assert (logm (expm ([0 1i; -1i 0])), [0 1i; -1i 0], 10 * eps)
29738
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
194 %!test <*60738>
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
195 %! A = [0.2510, 1.2808, -1.2252; ...
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
196 %! 0.2015, 1.0766, 0.5630; ...
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
197 %! -1.9769, -1.0922, -0.5831];
29805
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
198 %! if (ismac ())
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
199 %! ## The math libraries on macOS seem to require larger tolerances
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
200 %! tol = 60*eps;
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
201 %! else
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
202 %! tol = 40*eps;
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
203 %! endif
29738
5928dd4f7a02 logm.m: Fix check for real negative values in complex vector (bug #60738).
Markus Mützel <markus.muetzel@gmx.de>
parents: 29358
diff changeset
204 %! warning ("off", "Octave:logm:non-principal", "local");
29805
20380c9bed30 logm.m: Allow larger tolerance for test on macOS.
Markus Mützel <markus.muetzel@gmx.de>
parents: 29770
diff changeset
205 %! assert (expm (logm (A)), A, tol);
31551
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31253
diff changeset
206 %!assert (expm (logm (eye (3))), eye (3))
fd29c7a50a78 maint: use commas, semicolons consistently with Octave conventions.
Rik <rik@octave.org>
parents: 31253
diff changeset
207 %!assert (expm (logm (zeros (3))), zeros (3))
11472
1740012184f9 Use uppercase for variable names in error() strings to match Info documentation. Only m-files done.
Rik <octave@nomad.inbox5.com>
parents: 11471
diff changeset
208
19833
9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions.
Rik <rik@octave.org>
parents: 19697
diff changeset
209 ## Test input validation
28896
90fea9cc9caa test: Add expected error message <Invalid call> to BIST tests for nargin.
Rik <rik@octave.org>
parents: 28789
diff changeset
210 %!error <Invalid call> logm ()
14363
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks
Rik <octave@nomad.inbox5.com>
parents: 14327
diff changeset
211 %!error <logm: A must be a square matrix> logm ([1 0;0 1; 2 2])