Mercurial > jwe > octave
view scripts/linear-algebra/issymmetric.m @ 20160:03b9d17a2d95 stable
doc: Update more docstrings to have one sentence summary as first line.
Reviewed io, java, linear-algebra, prefs, and set script directories.
* scripts/io/beep.m, scripts/io/dlmwrite.m, scripts/io/importdata.m,
scripts/io/strread.m, scripts/io/textread.m, scripts/java/javaArray.m,
scripts/java/java_get.m, scripts/java/java_set.m, scripts/java/javaaddpath.m,
scripts/java/javachk.m, scripts/java/javaclasspath.m, scripts/java/javamem.m,
scripts/java/javarmpath.m, scripts/linear-algebra/bandwidth.m,
scripts/linear-algebra/commutation_matrix.m, scripts/linear-algebra/cond.m,
scripts/linear-algebra/condest.m, scripts/linear-algebra/cross.m,
scripts/linear-algebra/duplication_matrix.m, scripts/linear-algebra/expm.m,
scripts/linear-algebra/housh.m, scripts/linear-algebra/isdefinite.m,
scripts/linear-algebra/ishermitian.m, scripts/linear-algebra/issymmetric.m,
scripts/linear-algebra/istril.m, scripts/linear-algebra/istriu.m,
scripts/linear-algebra/krylov.m, scripts/linear-algebra/logm.m,
scripts/linear-algebra/normest.m, scripts/linear-algebra/null.m,
scripts/linear-algebra/onenormest.m, scripts/linear-algebra/orth.m,
scripts/linear-algebra/qzhess.m, scripts/linear-algebra/rank.m,
scripts/linear-algebra/rref.m, scripts/linear-algebra/vech.m,
scripts/path/matlabroot.m, scripts/prefs/addpref.m, scripts/prefs/getpref.m,
scripts/prefs/ispref.m, scripts/prefs/rmpref.m, scripts/prefs/setpref.m,
scripts/set/powerset.m, scripts/set/setdiff.m:
Update more docstrings to have one sentence summary as first line.
author | Rik <rik@octave.org> |
---|---|
date | Sun, 03 May 2015 15:36:23 -0700 |
parents | 4197fc428c7d |
children | 516bb87ea72e |
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## Copyright (C) 1996-2015 John W. Eaton ## Copyright (C) 2009 VZLU Prague ## ## This file is part of Octave. ## ## Octave is free software; you can redistribute it and/or modify it ## under the terms of the GNU General Public License as published by ## the Free Software Foundation; either version 3 of the License, or (at ## your option) any later version. ## ## Octave is distributed in the hope that it will be useful, but ## WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU ## General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with Octave; see the file COPYING. If not, see ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} issymmetric (@var{A}) ## @deftypefnx {Function File} {} issymmetric (@var{A}, @var{tol}) ## Return true if @var{A} is a symmetric matrix within the tolerance specified ## by @var{tol}. ## ## The default tolerance is zero (uses faster code). ## ## Matrix @var{A} is considered symmetric if ## @code{norm (@var{A} - @var{A}.', Inf) / norm (@var{A}, Inf) < @var{tol}}. ## @seealso{ishermitian, isdefinite} ## @end deftypefn ## Author: A. S. Hodel <scotte@eng.auburn.edu> ## Created: August 1993 ## Adapted-By: jwe function retval = issymmetric (A, tol = 0) if (nargin < 1 || nargin > 2) print_usage (); endif retval = (isnumeric (A) || islogical (A)) && issquare (A); if (retval) if (tol == 0) ## Handle large sparse matrices as well as full ones retval = nnz (A != A.') == 0; else norm_x = norm (A, inf); retval = norm_x == 0 || norm (A - A.', inf) / norm_x <= tol; endif endif endfunction %!assert (issymmetric (1)) %!assert (! issymmetric ([1, 2])) %!assert (issymmetric ([])) %!assert (issymmetric ([1, 2; 2, 1])) %!assert (! (issymmetric ("test"))) %!assert (issymmetric ([1, 2.1; 2, 1.1], 0.2)) %!assert (issymmetric ([1, 2i; 2i, 1])) %!assert (! (issymmetric ("t"))) %!assert (! (issymmetric (["te"; "et"]))) %!assert (issymmetric (speye (100000))) %!assert (issymmetric (logical (eye (2)))) %!test %! s.a = 1; %! assert (! issymmetric (s)); %!error issymmetric ([1, 2; 2, 1], 0, 0) %!error issymmetric ()