Mercurial > octave-nkf
view src/DLD-FUNCTIONS/inv.cc @ 7017:a1dbe9d80eee
[project @ 2007-10-12 21:27:11 by jwe]
author | jwe |
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date | Fri, 12 Oct 2007 21:27:37 +0000 |
parents | 93c65f2a5668 |
children | f3c00dc0912b |
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/* Copyright (C) 1996, 1997, 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "defun-dld.h" #include "error.h" #include "gripes.h" #include "oct-obj.h" #include "utils.h" DEFUN_DLD (inv, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Loadable Function} {[@var{x}, @var{rcond}] = } inv (@var{a})\n\ @deftypefnx {Loadable Function} {[@var{x}, @var{rcond}] = } inverse (@var{a})\n\ Compute the inverse of the square matrix @var{a}. Return an estimate\n\ of the reciprocal condition number if requested, otherwise warn of an\n\ ill-conditioned matrix if the reciprocal condition number is small.\n\ @end deftypefn") { octave_value_list retval; int nargin = args.length (); if (nargin != 1) { print_usage (); return retval; } octave_value arg = args(0); octave_idx_type nr = arg.rows (); octave_idx_type nc = arg.columns (); int arg_is_empty = empty_arg ("inverse", nr, nc); if (arg_is_empty < 0) return retval; else if (arg_is_empty > 0) return octave_value (Matrix ()); if (nr != nc) { gripe_square_matrix_required ("inverse"); return retval; } if (arg.is_real_type ()) { Matrix m = arg.matrix_value (); if (! error_state) { MatrixType mattyp = args(0).matrix_type (); octave_idx_type info; double rcond = 0.0; Matrix result = m.inverse (mattyp, info, rcond, 1); args(0).matrix_type (mattyp); if (nargout > 1) retval(1) = rcond; retval(0) = result; volatile double xrcond = rcond; xrcond += 1.0; if (nargout < 2 && (info == -1 || xrcond == 1.0)) warning ("inverse: matrix singular to machine precision,\ rcond = %g", rcond); } } else if (arg.is_complex_type ()) { ComplexMatrix m = arg.complex_matrix_value (); if (! error_state) { MatrixType mattyp = args(0).matrix_type (); octave_idx_type info; double rcond = 0.0; ComplexMatrix result = m.inverse (mattyp, info, rcond, 1); args(0).matrix_type (mattyp); if (nargout > 1) retval(1) = rcond; retval(0) = result; volatile double xrcond = rcond; xrcond += 1.0; if (nargout < 2 && (info == -1 || xrcond == 1.0)) warning ("inverse: matrix singular to machine precision,\ rcond = %g", rcond); } } else { gripe_wrong_type_arg ("inv", arg); } return retval; } // FIXME -- this should really be done with an alias, but // alias_builtin() won't do the right thing if we are actually using // dynamic linking. DEFUN_DLD (inverse, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Loadable Function} {} inverse (@var{a})\n\ See inv.\n\ @end deftypefn") { return Finv (args, nargout); } /* ;;; Local Variables: *** ;;; mode: C++ *** ;;; End: *** */