octave: scripts/specfun/factor.m annotate

annotate scripts/specfun/factor.m @ 28891:de5f2f9a64ff

maint: Use same coding style when checking for a minimum of 1 input. * disp.m, __get_properties__.m, disp.m, isplaying.m, pause.m, resume.m, stop.m, __get_properties__.m, disp.m, isrecording.m, pause.m, resume.m, stop.m, mu2lin.m, acosd.m, acot.m, acotd.m, acoth.m, acsc.m, acscd.m, acsch.m, asec.m, asecd.m, asech.m, asind.m, atand.m, cosd.m, cot.m, cotd.m, coth.m, csc.m, cscd.m, csch.m, sec.m, secd.m, sech.m, sind.m, tand.m, cell2mat.m, deg2rad.m, fliplr.m, flipud.m, int2str.m, nextpow2.m, num2str.m, rad2deg.m, subsindex.m, rotx.m, roty.m, rotz.m, voronoin.m, __unimplemented__.m, frame2im.m, hsv2rgb.m, iscolormap.m, __imfinfo__.m, rgb2gray.m, rgb2hsv.m, fileread.m, is_valid_file_id.m, usejava.m, argnames.m, char.m, formula.m, vectorize.m, isdir.m, vectorize.m, condeig.m, duplication_matrix.m, expm.m, isdiag.m, istril.m, istriu.m, normest.m, planerot.m, trace.m, vech.m, fieldnames.m, fileparts.m, grabcode.m, isfile.m, isfolder.m, mustBeFinite.m, mustBeInteger.m, mustBeNegative.m, mustBeNonNan.m, mustBeNonempty.m, mustBeNonnegative.m, mustBeNonpositive.m, mustBeNonsparse.m, mustBeNonzero.m, mustBeNumeric.m, mustBeNumericOrLogical.m, mustBePositive.m, mustBeReal.m, namedargs2cell.m, open.m, run.m, swapbytes.m, pareto.m, allchild.m, colstyle.m, hdl2struct.m, isaxes.m, isfigure.m, ishandle.m, compan.m, poly.m, polyreduce.m, ppjumps.m, roots.m, unmkpp.m, profexplore.m, profile.m, bartlett.m, fftshift.m, hurst.m, ifftshift.m, sinc.m, spencer.m, yulewalker.m, colperm.m, nonzeros.m, spconvert.m, spones.m, sprandsym.m, cosint.m, expint.m, factor.m, factorial.m, isprime.m, perms.m, primes.m, reallog.m, realsqrt.m, sinint.m, gallery.m, hadamard.m, hilb.m, invhilb.m, magic.m, wilkinson.m, center.m, iqr.m, meansq.m, median.m, runlength.m, bin2dec.m, blanks.m, deblank.m, hex2dec.m, isletter.m, isstring.m, str2num.m, strtrim.m, asctime.m, ctime.m: Replace "if (nargin != 1)" formulations with "if (nargin < 1)" to match the rest of Octave.

author	Rik <rik@octave.org>
date	Sat, 10 Oct 2020 16:32:20 -0700
parents	a4268efb7334
children	90fea9cc9caa

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 ##
27919 1891570abac8 update Octave Project Developers copyright for the new year John W. Eaton <jwe@octave.org> parents: 27918 diff changeset	3 ## Copyright (C) 2000-2020 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/>.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	7 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	8 ## This file is part of Octave.
1fe78adb91bc [project @ 2006-05-22 06:25:14 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
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe 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: 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.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	14 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	15 ## Octave is distributed in the hope that it will be useful, but
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe 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.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	19 ##
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	20 ## You should have received a copy of the GNU General Public License
7016 93c65f2a5668 [project @ 2007-10-12 06:40:56 by jwe] jwe parents: 7001 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 ########################################################################
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	25
1fe78adb91bc [project @ 2006-05-22 06:25:14 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: 20486 diff changeset	27 ## @deftypefn {} {@var{pf} =} factor (@var{q})
516bb87ea72e 2015 Code Sprint: remove class of function from docstring for all m-files. Rik <rik@octave.org> parents: 20486 diff changeset	28 ## @deftypefnx {} {[@var{pf}, @var{n}] =} factor (@var{q})
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	29 ## Return the prime factorization of @var{q}.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	30 ##
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	31 ## The prime factorization is defined as @code{prod (@var{pf}) == @var{q}}
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	32 ## where every element of @var{pf} is a prime number. If @code{@var{q} == 1},
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	33 ## return 1. The output @var{pf} is of the same numeric class as the input.
19593 446c46af4b42 strip trailing whitespace from most source files John W. Eaton <jwe@octave.org> parents: 17744 diff changeset	34 ##
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	35 ## With two output arguments, return the unique prime factors @var{pf} and
21546 f7f97d7e9294 doc: Wrap m-file docstrings to 79 characters + newline (80 total). Rik <rik@octave.org> parents: 20852 diff changeset	36 ## their multiplicities. That is,
f7f97d7e9294 doc: Wrap m-file docstrings to 79 characters + newline (80 total). Rik <rik@octave.org> parents: 20852 diff changeset	37 ## @code{prod (@var{pf} .^ @var{n}) == @var{q}}.
19596 0e1f5a750d00 maint: Periodic merge of gui-release to default. John W. Eaton <jwe@octave.org> parents: 19152 19593 diff changeset	38 ##
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	39 ## Implementation Note: The input @var{q} must be less than @code{flintmax}
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	40 ## (9.0072e+15) in order to factor correctly.
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	41 ## @seealso{gcd, lcm, isprime, primes}
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	42 ## @end deftypefn
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	43
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	44 function [pf, n] = factor (q)
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	45
28891 de5f2f9a64ff maint: Use same coding style when checking for a minimum of 1 input. Rik <rik@octave.org> parents: 27978 diff changeset	46 if (nargin < 1)
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	47 print_usage ();
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	48 endif
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	49
25269 cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	50 if (! isscalar (q) \|\| ! isreal (q) \|\| q < 0 \|\| q != fix (q))
cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	51 error ("factor: Q must be a real non-negative integer");
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	52 endif
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	53
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	54 ## Special case of no primes less than sqrt(q).
c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	55 if (q < 4)
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	56 pf = q;
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	57 n = 1;
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	58 return;
11587 c792872f8942 all script files: untabify and strip trailing whitespace John W. Eaton <jwe@octave.org> parents: 11523 diff changeset	59 endif
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	60
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	61 cls = class (q); # store class
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	62 q = double (q); # internal algorithm relies on numbers being doubles.
17716 e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	63 qorig = q;
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	64 pf = [];
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	65 ## There is at most one prime greater than sqrt(q), and if it exists,
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	66 ## it has multiplicity 1, so no need to consider any factors greater
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	67 ## than sqrt(q) directly. [If there were two factors p1, p2 > sqrt(q),
21751 b571fc85953f maint: Use two spaces after period to indicate sentence break. Rik <rik@octave.org> parents: 21546 diff changeset	68 ## then q >= p1p2 > sqrt(q)sqrt(q) == q. Contradiction.]
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	69 p = primes (sqrt (q));
c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	70 while (q > 1)
c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	71 ## Find prime factors in remaining q.
17716 e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	72 p = p(rem (q, p) == 0);
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	73 if (isempty (p))
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	74 ## Can't be reduced further, so q must itself be a prime.
c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	75 p = q;
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	76 endif
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	77 pf = [pf, p];
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	78 ## Reduce q.
17716 e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	79 q /= prod (p);
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	80 endwhile
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	81 pf = sort (pf);
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	82
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	83 ## Verify algorithm was successful
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	84 q = prod (pf);
17716 e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	85 if (q != qorig)
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	86 error ("factor: Q too large to factor");
20486 4bb41929286b Deprecate bitmax. Kai T. Ohlhus <k.ohlhus@gmail.com> parents: 19833 diff changeset	87 elseif (q >= flintmax ())
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	88 warning ("factor: Q too large. Answer is unreliable");
17716 e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	89 endif
e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	90
25269 cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	91 ## Determine multiplicity.
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	92 if (nargout > 1)
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	93 idx = find ([0, pf] != [pf, 0]);
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	94 pf = pf(idx(1:length (idx)-1));
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	95 n = diff (idx);
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	96 endif
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	97
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	98 ## Restore class of input
25436 996d78102a71 maint: Strip trailing whitespace from source files. John W. Eaton <jwe@octave.org> parents: 25270 diff changeset	99 pf = feval (cls, pf);
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	100
5827 1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	101 endfunction
1fe78adb91bc [project @ 2006-05-22 06:25:14 by jwe] jwe parents: diff changeset	102
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	103
f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	104 %!assert (factor (1), 1)
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	105 %!test
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	106 %! for i = 2:20
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	107 %! pf = factor (i);
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	108 %! assert (prod (pf), i);
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	109 %! assert (all (isprime (pf)));
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	110 %! [pf, n] = factor (i);
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	111 %! assert (prod (pf.^n), i);
e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	112 %! assert (all ([0,pf] != [pf,0]));
14363 f3d52523cde1 Use Octave coding conventions in all m-file %!test blocks Rik <octave@nomad.inbox5.com> parents: 14138 diff changeset	113 %! endfor
11469 c776f063fefe Overhaul m-script files to use common variable name between code and documentation. Rik <octave@nomad.inbox5.com> parents: 10476 diff changeset	114
25270 617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	115 %!assert (factor (uint8 (8)), uint8 ([2 2 2]))
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	116 %!assert (factor (single (8)), single ([2 2 2]))
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	117 %!test
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	118 %! [pf, n] = factor (int16 (8));
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	119 %! assert (pf, int16 (2));
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	120 %! assert (n, double (3));
617fe022e965 factor.m: Return output factors of same class as input for Matlab compatibility. Rik <rik@octave.org> parents: 25269 diff changeset	121
19833 9fc020886ae9 maint: Clean up m-files to follow Octave coding conventions. Rik <rik@octave.org> parents: 19697 diff changeset	122 ## Test input validation
17716 e48f5a52e838 factor.m: Warn when the input is too large to calculate reliable answer. Doug Stewart <doug.dastew@gmail.com> parents: 14868 diff changeset	123 %!error factor ()
19097 e7bffcea619f factor.m: Overhaul function. Rik <rik@octave.org> parents: 17744 diff changeset	124 %!error factor (1,2)
25269 cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	125 %!error <Q must be a real non-negative integer> factor (6i)
cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	126 %!error <Q must be a real non-negative integer> factor ([1,2])
cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	127 %!error <Q must be a real non-negative integer> factor (1.5)
cac96fd5310d factor.m: Emit an error if input is negative (bug #53425). Dildar Sk <dildarsk101010@gmail.com> parents: 25054 diff changeset	128 %!error <Q must be a real non-negative integer> factor (-20)

Mercurial > octave

annotate scripts/specfun/factor.m @ 28891:de5f2f9a64ff