Mercurial > octave
annotate src/DLD-FUNCTIONS/eig.cc @ 7578:91f8446ce4ae
handle possible error from EIG
| author | John W. Eaton <jwe@octave.org> |
|---|---|
| date | Tue, 11 Mar 2008 10:49:33 -0400 |
| parents | a1dbe9d80eee |
| children | 82be108cc558 72830070a17b |
| rev | line source |
|---|---|
| 2928 | 1 /* |
| 2 | |
| 7017 | 3 Copyright (C) 1996, 1997, 1999, 2000, 2003, 2004, 2005, 2006, 2007 |
| 4 John W. Eaton | |
| 2928 | 5 |
| 6 This file is part of Octave. | |
| 7 | |
| 8 Octave is free software; you can redistribute it and/or modify it | |
| 9 under the terms of the GNU General Public License as published by the | |
| 7016 | 10 Free Software Foundation; either version 3 of the License, or (at your |
| 11 option) any later version. | |
| 2928 | 12 |
| 13 Octave is distributed in the hope that it will be useful, but WITHOUT | |
| 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 16 for more details. | |
| 17 | |
| 18 You should have received a copy of the GNU General Public License | |
| 7016 | 19 along with Octave; see the file COPYING. If not, see |
| 20 <http://www.gnu.org/licenses/>. | |
| 2928 | 21 |
| 22 */ | |
| 23 | |
| 24 #ifdef HAVE_CONFIG_H | |
| 25 #include <config.h> | |
| 26 #endif | |
| 27 | |
| 28 #include "EIG.h" | |
| 29 | |
| 30 #include "defun-dld.h" | |
| 31 #include "error.h" | |
| 32 #include "gripes.h" | |
| 33 #include "oct-obj.h" | |
| 34 #include "utils.h" | |
| 35 | |
| 36 DEFUN_DLD (eig, args, nargout, | |
| 3548 | 37 "-*- texinfo -*-\n\ |
| 3372 | 38 @deftypefn {Loadable Function} {@var{lambda} =} eig (@var{a})\n\ |
| 39 @deftypefnx {Loadable Function} {[@var{v}, @var{lambda}] =} eig (@var{a})\n\ | |
| 40 The eigenvalues (and eigenvectors) of a matrix are computed in a several\n\ | |
| 41 step process which begins with a Hessenberg decomposition, followed by a\n\ | |
| 42 Schur decomposition, from which the eigenvalues are apparent. The\n\ | |
| 43 eigenvectors, when desired, are computed by further manipulations of the\n\ | |
| 44 Schur decomposition.\n\ | |
| 5829 | 45 \n\ |
| 46 The eigenvalues returned by @code{eig} are not ordered.\n\ | |
| 3372 | 47 @end deftypefn") |
| 2928 | 48 { |
| 49 octave_value_list retval; | |
| 50 | |
| 51 int nargin = args.length (); | |
| 52 | |
| 53 if (nargin != 1 || nargout > 2) | |
| 54 { | |
| 5823 | 55 print_usage (); |
| 2928 | 56 return retval; |
| 57 } | |
| 58 | |
| 59 octave_value arg = args(0); | |
| 60 | |
| 5275 | 61 octave_idx_type nr = arg.rows (); |
| 62 octave_idx_type nc = arg.columns (); | |
| 2928 | 63 |
| 64 int arg_is_empty = empty_arg ("eig", nr, nc); | |
| 65 if (arg_is_empty < 0) | |
| 66 return retval; | |
| 67 else if (arg_is_empty > 0) | |
| 68 return octave_value_list (2, Matrix ()); | |
| 69 | |
| 70 if (nr != nc) | |
| 71 { | |
| 72 gripe_square_matrix_required ("eig"); | |
| 73 return retval; | |
| 74 } | |
| 75 | |
| 76 Matrix tmp; | |
| 77 ComplexMatrix ctmp; | |
| 78 EIG result; | |
| 79 | |
| 80 if (arg.is_real_type ()) | |
| 81 { | |
| 82 tmp = arg.matrix_value (); | |
| 83 | |
| 84 if (error_state) | |
| 85 return retval; | |
| 86 else | |
| 4725 | 87 result = EIG (tmp, nargout > 1); |
| 2928 | 88 } |
| 89 else if (arg.is_complex_type ()) | |
| 90 { | |
| 91 ctmp = arg.complex_matrix_value (); | |
| 92 | |
| 93 if (error_state) | |
| 94 return retval; | |
| 95 else | |
| 4725 | 96 result = EIG (ctmp, nargout > 1); |
| 2928 | 97 } |
| 98 else | |
| 99 { | |
| 100 gripe_wrong_type_arg ("eig", tmp); | |
| 101 return retval; | |
| 102 } | |
| 103 | |
|
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104 if (! error_state) |
| 2928 | 105 { |
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106 if (nargout == 0 || nargout == 1) |
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107 { |
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108 retval(0) = result.eigenvalues (); |
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109 } |
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110 else |
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111 { |
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112 // Blame it on Matlab. |
| 2928 | 113 |
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parents:
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114 ComplexDiagMatrix d (result.eigenvalues ()); |
| 2928 | 115 |
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91f8446ce4ae
handle possible error from EIG
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parents:
7017
diff
changeset
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116 retval(1) = d; |
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91f8446ce4ae
handle possible error from EIG
John W. Eaton <jwe@octave.org>
parents:
7017
diff
changeset
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117 retval(0) = result.eigenvectors (); |
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91f8446ce4ae
handle possible error from EIG
John W. Eaton <jwe@octave.org>
parents:
7017
diff
changeset
|
118 } |
| 2928 | 119 } |
| 120 | |
| 121 return retval; | |
| 122 } | |
| 123 | |
| 124 /* | |
| 125 ;;; Local Variables: *** | |
| 126 ;;; mode: C++ *** | |
| 127 ;;; End: *** | |
| 128 */ |