Functions | Variables

svd.cc File Reference

#include "CmplxSVD.h"
#include "dbleSVD.h"
#include "fCmplxSVD.h"
#include "floatSVD.h"
#include "defun-dld.h"
#include "error.h"
#include "gripes.h"
#include "oct-obj.h"
#include "pr-output.h"
#include "utils.h"
#include "variables.h"
Include dependency graph for svd.cc:

Go to the source code of this file.

Functions

 DEFUN_DLD (svd, args, nargout,"-*- texinfo -*-\n\ @deftypefn {Loadable Function} {@var{s} =} svd (@var{A})\n\ @deftypefnx {Loadable Function} {[@var{U}, @var{S}, @var{V}] =} svd (@var{A})\n\ @deftypefnx {Loadable Function} {[@var{U}, @var{S}, @var{V}] =} svd (@var{A}, @var{econ})\n\ @cindex singular value decomposition\n\ Compute the singular value decomposition of @var{A}\n\ @tex\n\ $$\n\ A = U S V^{\\dagger}\n\ $$\n\ @end tex\n\ @ifnottex\n\ \n\ @example\n\ A = U*S*V'\n\ @end example\n\ \n\ @end ifnottex\n\ \n\ The function @code{svd} normally returns only the vector of singular values.\n\ When called with three return values, it computes\n\ @tex\n\ $U$, $S$, and $V$.\n\ @end tex\n\ @ifnottex\n\ @var{U}, @var{S}, and @var{V}.\n\ @end ifnottex\n\ For example,\n\ \n\ @example\n\ svd (hilb (3))\n\ @end example\n\ \n\ @noindent\n\ returns\n\ \n\ @example\n\ @group\n\ ans =\n\ \n\ 1.4083189\n\ 0.1223271\n\ 0.0026873\n\ @end group\n\ @end example\n\ \n\ @noindent\n\ and\n\ \n\ @example\n\ [u, s, v] = svd (hilb (3))\n\ @end example\n\ \n\ @noindent\n\ returns\n\ \n\ @example\n\ @group\n\ u =\n\ \n\ -0.82704 0.54745 0.12766\n\ -0.45986 -0.52829 -0.71375\n\ -0.32330 -0.64901 0.68867\n\ \n\ s =\n\ \n\ 1.40832 0.00000 0.00000\n\ 0.00000 0.12233 0.00000\n\ 0.00000 0.00000 0.00269\n\ \n\ v =\n\ \n\ -0.82704 0.54745 0.12766\n\ -0.45986 -0.52829 -0.71375\n\ -0.32330 -0.64901 0.68867\n\ @end group\n\ @end example\n\ \n\ If given a second argument, @code{svd} returns an economy-sized\n\ decomposition, eliminating the unnecessary rows or columns of @var{U} or\n\ @var{V}.\n\ @seealso{svd_driver, svds, eig}\n\ @end deftypefn")
 DEFUN_DLD (svd_driver, args, nargout,"-*- texinfo -*-\n\ @deftypefn {Loadable Function} {@var{val} =} svd_driver ()\n\ @deftypefnx {Loadable Function} {@var{old_val} =} svd_driver (@var{new_val})\n\ @deftypefnx {Loadable Function} {} svd_driver (@var{new_val}, \"local\")\n\ Query or set the underlying @sc{lapack} driver used by @code{svd}.\n\ Currently recognized values are \"gesvd\" and \"gesdd\". The default\n\ is \"gesvd\".\n\ \n\ When called from inside a function with the \"local\" option, the variable is\n\ changed locally for the function and any subroutines it calls. The original\n\ variable value is restored when exiting the function.\n\ @seealso{svd}\n\ @end deftypefn")

Variables

static int Vsvd_driver = SVD::GESVD

Function Documentation

DEFUN_DLD ( svd  ,
args  ,
nargout   
)
DEFUN_DLD ( svd_driver  ,
args  ,
nargout   
)

Definition at line 407 of file svd.cc.

References SET_INTERNAL_VARIABLE_CHOICES.


Variable Documentation

int Vsvd_driver = SVD::GESVD [static]

Definition at line 40 of file svd.cc.

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