Mercurial > hg > octave-nkf
diff src/svd.cc @ 1:78fd87e624cb
[project @ 1993-08-08 01:13:40 by jwe]
Initial revision
author | jwe |
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date | Sun, 08 Aug 1993 01:13:40 +0000 |
parents | |
children | d68036bcad4c |
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new file mode 100644 --- /dev/null +++ b/src/svd.cc @@ -0,0 +1,149 @@ +// tc-svd.cc -*- C++ -*- +/* + +Copyright (C) 1993 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 __GNUG__ +#pragma implementation +#endif + +#include "Matrix.h" + +#include "tree-const.h" +#include "user-prefs.h" +#include "gripes.h" +#include "error.h" + +#ifdef WITH_DLD +tree_constant * +builtin_svd_2 (tree_constant *args, int nargin, int nargout) +{ + return svd (args, nargin, nargout); +} +#endif + +tree_constant * +svd (tree_constant *args, int nargin, int nargout) +{ + tree_constant *retval = NULL_TREE_CONST; + + tree_constant arg = args[1].make_numeric (); + + if (arg.rows () == 0 || arg.columns () == 0) + { + int flag = user_pref.propagate_empty_matrices; + if (flag != 0) + { + if (flag < 0) + gripe_empty_arg ("svd", 0); + Matrix m; + retval = new tree_constant [4]; + retval[0] = tree_constant (m); + retval[1] = tree_constant (m); + retval[2] = tree_constant (m); + } + else + gripe_empty_arg ("svd", 1); + + return retval; + } + + Matrix tmp; + ComplexMatrix ctmp; + switch (arg.const_type ()) + { + case tree_constant_rep::scalar_constant: + tmp.resize (1, 1); + tmp.elem (0, 0) = arg.double_value (); + break; + case tree_constant_rep::matrix_constant: + tmp = arg.matrix_value (); + break; + case tree_constant_rep::complex_scalar_constant: + ctmp.resize (1, 1); + ctmp.elem (0, 0) = arg.complex_value (); + break; + case tree_constant_rep::complex_matrix_constant: + ctmp = arg.complex_matrix_value (); + break; + default: + panic_impossible (); + break; + } + + switch (arg.const_type ()) + { + case tree_constant_rep::scalar_constant: + case tree_constant_rep::matrix_constant: + { + SVD result (tmp); + + DiagMatrix sigma = result.singular_values (); + + if (nargout == 1) + { + retval = new tree_constant [2]; + retval[0] = tree_constant (sigma.diag (), 1); + } + else + { + retval = new tree_constant [4]; + retval[0] = tree_constant (result.left_singular_matrix ()); + retval[1] = tree_constant (sigma); + retval[2] = tree_constant (result.right_singular_matrix ()); + } + } + break; + case tree_constant_rep::complex_scalar_constant: + case tree_constant_rep::complex_matrix_constant: + { + ComplexSVD result (ctmp); + + DiagMatrix sigma = result.singular_values (); + + if (nargout == 1) + { + retval = new tree_constant [2]; + retval[0] = tree_constant (sigma.diag (), 1); + } + else + { + retval = new tree_constant [4]; + retval[0] = tree_constant (result.left_singular_matrix ()); + retval[1] = tree_constant (sigma); + retval[2] = tree_constant (result.right_singular_matrix ()); + } + } + break; + default: + panic_impossible (); + break; + } + + return retval; +} + +/* +;;; Local Variables: *** +;;; mode: C++ *** +;;; page-delimiter: "^/\\*" *** +;;; End: *** +*/