Mercurial > octave-nkf
view libinterp/corefcn/syl.cc @ 18518:0bdecd41b2dd stable
correctly size fread result (bug #41648)
* oct-stream.cc (octave_base_stream::read): When reading to EOF, don't
add extra column to the result matrix if the number of elements found
is an exact multiple of the number of rows requested.
Avoid mixed signed/unsigned comparisons.
* io.tst: New tests.
author | John W. Eaton <jwe@octave.org> |
---|---|
date | Sat, 22 Feb 2014 13:06:18 -0500 |
parents | 175b392e91fe |
children |
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/* Copyright (C) 1996-2013 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/>. */ // Author: A. S. Hodel <scotte@eng.auburn.edu> #ifdef HAVE_CONFIG_H #include <config.h> #endif #include "defun.h" #include "error.h" #include "gripes.h" #include "oct-obj.h" #include "utils.h" DEFUN (syl, args, nargout, "-*- texinfo -*-\n\ @deftypefn {Built-in Function} {@var{x} =} syl (@var{A}, @var{B}, @var{C})\n\ Solve the Sylvester equation\n\ @tex\n\ $$\n\ A X + X B + C = 0\n\ $$\n\ @end tex\n\ @ifnottex\n\ \n\ @example\n\ A X + X B + C = 0\n\ @end example\n\ \n\ @end ifnottex\n\ using standard @sc{lapack} subroutines. For example:\n\ \n\ @example\n\ @group\n\ syl ([1, 2; 3, 4], [5, 6; 7, 8], [9, 10; 11, 12])\n\ @result{} [ -0.50000, -0.66667; -0.66667, -0.50000 ]\n\ @end group\n\ @end example\n\ @end deftypefn") { octave_value retval; int nargin = args.length (); if (nargin != 3 || nargout > 1) { print_usage (); return retval; } octave_value arg_a = args(0); octave_value arg_b = args(1); octave_value arg_c = args(2); octave_idx_type a_nr = arg_a.rows (); octave_idx_type a_nc = arg_a.columns (); octave_idx_type b_nr = arg_b.rows (); octave_idx_type b_nc = arg_b.columns (); octave_idx_type c_nr = arg_c.rows (); octave_idx_type c_nc = arg_c.columns (); int arg_a_is_empty = empty_arg ("syl", a_nr, a_nc); int arg_b_is_empty = empty_arg ("syl", b_nr, b_nc); int arg_c_is_empty = empty_arg ("syl", c_nr, c_nc); bool isfloat = arg_a.is_single_type () || arg_b.is_single_type () || arg_c.is_single_type (); if (arg_a_is_empty > 0 && arg_b_is_empty > 0 && arg_c_is_empty > 0) if (isfloat) return octave_value (FloatMatrix ()); else return octave_value (Matrix ()); else if (arg_a_is_empty || arg_b_is_empty || arg_c_is_empty) return retval; // Arguments are not empty, so check for correct dimensions. if (a_nr != a_nc || b_nr != b_nc) { gripe_square_matrix_required ("syl: first two parameters:"); return retval; } else if (a_nr != c_nr || b_nr != c_nc) { gripe_nonconformant (); return retval; } // Dimensions look o.k., let's solve the problem. if (isfloat) { if (arg_a.is_complex_type () || arg_b.is_complex_type () || arg_c.is_complex_type ()) { // Do everything in complex arithmetic; FloatComplexMatrix ca = arg_a.float_complex_matrix_value (); if (error_state) return retval; FloatComplexMatrix cb = arg_b.float_complex_matrix_value (); if (error_state) return retval; FloatComplexMatrix cc = arg_c.float_complex_matrix_value (); if (error_state) return retval; retval = Sylvester (ca, cb, cc); } else { // Do everything in real arithmetic. FloatMatrix ca = arg_a.float_matrix_value (); if (error_state) return retval; FloatMatrix cb = arg_b.float_matrix_value (); if (error_state) return retval; FloatMatrix cc = arg_c.float_matrix_value (); if (error_state) return retval; retval = Sylvester (ca, cb, cc); } } else { if (arg_a.is_complex_type () || arg_b.is_complex_type () || arg_c.is_complex_type ()) { // Do everything in complex arithmetic; ComplexMatrix ca = arg_a.complex_matrix_value (); if (error_state) return retval; ComplexMatrix cb = arg_b.complex_matrix_value (); if (error_state) return retval; ComplexMatrix cc = arg_c.complex_matrix_value (); if (error_state) return retval; retval = Sylvester (ca, cb, cc); } else { // Do everything in real arithmetic. Matrix ca = arg_a.matrix_value (); if (error_state) return retval; Matrix cb = arg_b.matrix_value (); if (error_state) return retval; Matrix cc = arg_c.matrix_value (); if (error_state) return retval; retval = Sylvester (ca, cb, cc); } } return retval; } /* %!assert (syl ([1, 2; 3, 4], [5, 6; 7, 8], [9, 10; 11, 12]), [-1/2, -2/3; -2/3, -1/2], sqrt (eps)) %!assert (syl (single ([1, 2; 3, 4]), single ([5, 6; 7, 8]), single ([9, 10; 11, 12])), single ([-1/2, -2/3; -2/3, -1/2]), sqrt (eps ("single"))) %!error syl () %!error syl (1, 2, 3, 4) %!error <must be a square matrix> syl ([1, 2; 3, 4], [1, 2, 3; 4, 5, 6], [4, 3]) */