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1 /* |
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2 |
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3 Copyright (C) 1996, 1997, 1999, 2000, 2001, 2002, 2004, 2005, 2006, |
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4 2007 John W. Eaton |
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5 |
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6 This file is part of Octave. |
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7 |
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8 Octave is free software; you can redistribute it and/or modify it |
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9 under the terms of the GNU General Public License as published by the |
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10 Free Software Foundation; either version 3 of the License, or (at your |
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11 option) any later version. |
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12 |
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13 Octave is distributed in the hope that it will be useful, but WITHOUT |
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14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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16 for more details. |
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17 |
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18 You should have received a copy of the GNU General Public License |
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19 along with Octave; see the file COPYING. If not, see |
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20 <http://www.gnu.org/licenses/>. |
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21 |
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22 */ |
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23 |
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24 #ifdef HAVE_CONFIG_H |
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25 #include <config.h> |
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26 #endif |
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27 |
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28 #include "defun-dld.h" |
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29 #include "error.h" |
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30 #include "gripes.h" |
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31 #include "oct-obj.h" |
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32 #include "utils.h" |
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33 |
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34 DEFUN_DLD (inv, args, nargout, |
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35 "-*- texinfo -*-\n\ |
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36 @deftypefn {Loadable Function} {[@var{x}, @var{rcond}] = } inv (@var{a})\n\ |
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37 @deftypefnx {Loadable Function} {[@var{x}, @var{rcond}] = } inverse (@var{a})\n\ |
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38 Compute the inverse of the square matrix @var{a}. Return an estimate\n\ |
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39 of the reciprocal condition number if requested, otherwise warn of an\n\ |
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40 ill-conditioned matrix if the reciprocal condition number is small.\n\ |
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41 @end deftypefn") |
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42 { |
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43 octave_value_list retval; |
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44 |
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45 int nargin = args.length (); |
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46 |
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47 if (nargin != 1) |
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48 { |
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49 print_usage (); |
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50 return retval; |
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51 } |
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52 |
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53 octave_value arg = args(0); |
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54 |
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55 octave_idx_type nr = arg.rows (); |
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56 octave_idx_type nc = arg.columns (); |
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57 |
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58 int arg_is_empty = empty_arg ("inverse", nr, nc); |
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59 |
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60 if (arg_is_empty < 0) |
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61 return retval; |
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62 else if (arg_is_empty > 0) |
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63 return octave_value (Matrix ()); |
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64 |
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65 if (nr != nc) |
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66 { |
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67 gripe_square_matrix_required ("inverse"); |
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68 return retval; |
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69 } |
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70 |
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71 if (arg.is_real_type ()) |
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72 { |
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73 Matrix m = arg.matrix_value (); |
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74 |
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75 if (! error_state) |
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76 { |
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77 MatrixType mattyp = args(0).matrix_type (); |
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78 |
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79 octave_idx_type info; |
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80 double rcond = 0.0; |
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81 |
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82 Matrix result = m.inverse (mattyp, info, rcond, 1); |
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83 |
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84 args(0).matrix_type (mattyp); |
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85 |
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86 if (nargout > 1) |
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87 retval(1) = rcond; |
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88 |
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89 retval(0) = result; |
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90 |
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91 volatile double xrcond = rcond; |
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92 xrcond += 1.0; |
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93 if (nargout < 2 && (info == -1 || xrcond == 1.0)) |
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94 warning ("inverse: matrix singular to machine precision,\ |
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95 rcond = %g", rcond); |
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96 } |
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97 } |
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98 else if (arg.is_complex_type ()) |
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99 { |
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100 ComplexMatrix m = arg.complex_matrix_value (); |
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101 |
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102 if (! error_state) |
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103 { |
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104 MatrixType mattyp = args(0).matrix_type (); |
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105 |
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106 octave_idx_type info; |
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107 double rcond = 0.0; |
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108 |
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109 ComplexMatrix result = m.inverse (mattyp, info, rcond, 1); |
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110 |
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111 args(0).matrix_type (mattyp); |
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112 |
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113 if (nargout > 1) |
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114 retval(1) = rcond; |
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115 |
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116 retval(0) = result; |
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117 |
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118 volatile double xrcond = rcond; |
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119 xrcond += 1.0; |
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120 if (nargout < 2 && (info == -1 || xrcond == 1.0)) |
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121 warning ("inverse: matrix singular to machine precision,\ |
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122 rcond = %g", rcond); |
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123 } |
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124 } |
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125 else |
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126 { |
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127 gripe_wrong_type_arg ("inv", arg); |
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128 } |
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129 |
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130 return retval; |
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131 } |
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132 |
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133 // FIXME -- this should really be done with an alias, but |
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134 // alias_builtin() won't do the right thing if we are actually using |
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135 // dynamic linking. |
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136 |
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137 DEFUN_DLD (inverse, args, nargout, |
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138 "-*- texinfo -*-\n\ |
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139 @deftypefn {Loadable Function} {} inverse (@var{a})\n\ |
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140 See inv.\n\ |
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141 @end deftypefn") |
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142 { |
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143 return Finv (args, nargout); |
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144 } |
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145 |
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146 /* |
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147 ;;; Local Variables: *** |
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148 ;;; mode: C++ *** |
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149 ;;; End: *** |
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150 */ |
