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comparison scripts/linear-algebra/issymmetric.m @ 18921:d0d0858cfab1

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doc: Match docstring variable names to function variable names for linear-algebra m-files. * isbanded.m, isdefinite.m, isdiag.m, ishermitian.m, issymmetric.m, istril.m, istriu.m: Use 'A' for input matrix in linear algebra routines. Change docstrings from 'x' to 'A'.
author Rik <rik@octave.org>
date Mon, 14 Jul 2014 08:54:45 -0700
parents 9cf6d5868d21
children
comparison
equal deleted inserted replaced
18920:c4def7ab39e7 18921:d0d0858cfab1
16 ## You should have received a copy of the GNU General Public License 16 ## You should have received a copy of the GNU General Public License
17 ## along with Octave; see the file COPYING. If not, see 17 ## along with Octave; see the file COPYING. If not, see
18 ## <http://www.gnu.org/licenses/>. 18 ## <http://www.gnu.org/licenses/>.
19 19
20 ## -*- texinfo -*- 20 ## -*- texinfo -*-
21 ## @deftypefn {Function File} {} issymmetric (@var{x}) 21 ## @deftypefn {Function File} {} issymmetric (@var{A})
22 ## @deftypefnx {Function File} {} issymmetric (@var{x}, @var{tol}) 22 ## @deftypefnx {Function File} {} issymmetric (@var{A}, @var{tol})
23 ## Return true if @var{x} is a symmetric matrix within the tolerance specified 23 ## Return true if @var{A} is a symmetric matrix within the tolerance specified
24 ## by @var{tol}. The default tolerance is zero (uses faster code). 24 ## by @var{tol}.
25 ## Matrix @var{x} is considered symmetric if 25 ##
26 ## @code{norm (@var{x} - @var{x}.', Inf) / norm (@var{x}, Inf) < @var{tol}}. 26 ## The default tolerance is zero (uses faster code).
27 ## Matrix @var{A} is considered symmetric if
28 ## @code{norm (@var{A} - @var{A}.', Inf) / norm (@var{A}, Inf) < @var{tol}}.
27 ## @seealso{ishermitian, isdefinite} 29 ## @seealso{ishermitian, isdefinite}
28 ## @end deftypefn 30 ## @end deftypefn
29 31
30 ## Author: A. S. Hodel <scotte@eng.auburn.edu> 32 ## Author: A. S. Hodel <scotte@eng.auburn.edu>
31 ## Created: August 1993 33 ## Created: August 1993
32 ## Adapted-By: jwe 34 ## Adapted-By: jwe
33 35
34 function retval = issymmetric (x, tol = 0) 36 function retval = issymmetric (A, tol = 0)
35 37
36 if (nargin < 1 || nargin > 2) 38 if (nargin < 1 || nargin > 2)
37 print_usage (); 39 print_usage ();
38 endif 40 endif
39 41
40 retval = (isnumeric (x) || islogical (x)) && issquare (x); 42 retval = (isnumeric (A) || islogical (A)) && issquare (A);
41 if (retval) 43 if (retval)
42 if (tol == 0) 44 if (tol == 0)
43 ## Handle large sparse matrices as well as full ones 45 ## Handle large sparse matrices as well as full ones
44 retval = nnz (x != x.') == 0; 46 retval = nnz (A != A.') == 0;
45 else 47 else
46 norm_x = norm (x, inf); 48 norm_x = norm (A, inf);
47 retval = norm_x == 0 || norm (x - x.', inf) / norm_x <= tol; 49 retval = norm_x == 0 || norm (A - A.', inf) / norm_x <= tol;
48 endif 50 endif
49 endif 51 endif
50 52
51 endfunction 53 endfunction
52 54