home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Cream of the Crop 26
/
Cream of the Crop 26.iso
/
os2
/
octa209s.zip
/
octave-2.09
/
src
/
svd.cc
< prev
next >
Wrap
C/C++ Source or Header
|
1996-11-03
|
3KB
|
143 lines
/*
Copyright (C) 1996 John W. Eaton
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 2, 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, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "CmplxSVD.h"
#include "dbleSVD.h"
#include "defun-dld.h"
#include "error.h"
#include "gripes.h"
#include "help.h"
#include "mappers.h"
#include "oct-obj.h"
#include "pr-output.h"
#include "utils.h"
DEFUN_DLD (svd, args, nargout,
"S = svd (X) or [U, S, V] = svd (X [, 0])\n\
\n\
Compute the singular value decomposition of X. Given a second input\n\
argument, an `economy' sized factorization is computed that omits\n\
unnecessary rows and columns of U and V.\n\
\n\
X may not contain any Inf or NaN values.")
{
octave_value_list retval;
int nargin = args.length ();
if (nargin < 1 || nargin > 2 || nargout == 2 || nargout > 3)
{
print_usage ("svd");
return retval;
}
octave_value arg = args(0);
int arg_is_empty = empty_arg ("svd", arg.rows (), arg.columns ());
if (arg_is_empty < 0)
return retval;
else if (arg_is_empty > 0)
return octave_value_list (3, Matrix ());
SVD::type type = ((nargout == 0 || nargout == 1)
? SVD::sigma_only
: (nargin == 2) ? SVD::economy : SVD::std);
if (arg.is_real_type ())
{
Matrix tmp = arg.matrix_value ();
if (! error_state)
{
if (tmp.any_element_is_inf_or_nan ())
{
error ("svd: cannot take SVD of matrix containing Inf or\
NaN values");
return retval;
}
SVD result (tmp, type);
DiagMatrix sigma = result.singular_values ();
if (nargout == 0 || nargout == 1)
{
retval(0) = octave_value (sigma.diag (), 1);
}
else
{
retval(2) = result.right_singular_matrix ();
retval(1) = sigma;
retval(0) = result.left_singular_matrix ();
}
}
}
else if (arg.is_complex_type ())
{
ComplexMatrix ctmp = arg.complex_matrix_value ();
if (! error_state)
{
if (ctmp.any_element_is_inf_or_nan ())
{
error ("svd: cannot take SVD of matrix containing Inf or\
NaN values");
return retval;
}
ComplexSVD result (ctmp, type);
DiagMatrix sigma = result.singular_values ();
if (nargout == 0 || nargout == 1)
{
retval(0) = octave_value (sigma.diag (), 1);
}
else
{
retval(2) = result.right_singular_matrix ();
retval(1) = sigma;
retval(0) = result.left_singular_matrix ();
}
}
}
else
{
gripe_wrong_type_arg ("svd", arg);
return retval;
}
return retval;
}
/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/