Mercurial > octave-libgccjit
view src/svd.cc @ 628:aecbe369233b
[project @ 1994-08-19 13:27:51 by jwe]
author | jwe |
---|---|
date | Fri, 19 Aug 1994 13:37:34 +0000 |
parents | 6636e6198f01 |
children | fae2bd91c027 |
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// f-svd.cc -*- C++ -*- /* Copyright (C) 1993, 1994 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, 675 Mass Ave, Cambridge, MA 02139, USA. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "dbleSVD.h" #include "CmplxSVD.h" #include "tree-const.h" #include "user-prefs.h" #include "gripes.h" #include "error.h" #include "utils.h" #include "help.h" #include "defun-dld.h" DEFUN_DLD ("svd", Fsvd, Ssvd, 2, 3, "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") { Octave_object retval (3, Matrix ()); int nargin = args.length (); if (nargin < 2 || nargin > 3 || nargout == 2 || nargout > 3) { print_usage ("svd"); return retval; } SVD::type type = (nargin == 3) ? SVD::economy : SVD::std; tree_constant arg = args(1); if (arg.is_real_type ()) { Matrix tmp = arg.matrix_value (); if (error_state || empty_arg ("svd", tmp.rows (), tmp.columns ())) return retval; SVD result (tmp, type); DiagMatrix sigma = result.singular_values (); if (nargout == 0 || nargout == 1) { retval(0) = tree_constant (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 || empty_arg ("svd", ctmp.rows (), ctmp.columns ())) return retval; ComplexSVD result (ctmp, type); DiagMatrix sigma = result.singular_values (); if (nargout == 0 || nargout == 1) { retval(0) = tree_constant (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++ *** ;;; page-delimiter: "^/\\*" *** ;;; End: *** */