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1 // f-inv.cc -*- C++ -*- |
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2 /* |
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3 |
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4 Copyright (C) 1993, 1994 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 2, or (at your option) any |
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11 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, write to the Free |
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20 Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. |
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21 |
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22 */ |
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23 |
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240
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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 "dMatrix.h" |
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29 #include "CMatrix.h" |
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30 |
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31 #include "tree-const.h" |
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32 #include "user-prefs.h" |
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33 #include "gripes.h" |
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34 #include "error.h" |
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35 #include "help.h" |
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36 #include "defun-dld.h" |
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37 |
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38 DEFUN_DLD ("inv", Finv, Sinv, 2, 1, |
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39 "inv (X): inverse of a square matrix") |
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40 { |
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41 Octave_object retval; |
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42 |
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43 int nargin = args.length (); |
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44 |
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45 if (nargin != 2) |
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46 { |
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47 print_usage ("inv"); |
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48 return retval; |
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49 } |
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50 |
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51 tree_constant tmp = args(1).make_numeric (); |
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52 |
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53 int nr = tmp.rows (); |
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54 int nc = tmp.columns (); |
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55 if (nr == 0 || nc == 0) |
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56 { |
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57 int flag = user_pref.propagate_empty_matrices; |
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58 if (flag < 0) |
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59 gripe_empty_arg ("inverse", 0); |
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60 else if (flag == 0) |
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61 gripe_empty_arg ("inverse", 1); |
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62 } |
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63 |
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64 Matrix mtmp; |
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65 if (nr == 0 && nc == 0) |
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66 return mtmp; |
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67 |
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68 if (tmp.is_real_matrix ()) |
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69 { |
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70 Matrix m = tmp.matrix_value (); |
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71 if (m.rows () == m.columns ()) |
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72 { |
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73 int info; |
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74 double rcond = 0.0; |
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75 Matrix minv = m.inverse (info, rcond); |
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76 if (info == -1) |
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77 warning ("inverse: matrix singular to machine precision,\ |
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78 rcond = %g", rcond); |
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79 else |
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80 retval = minv; |
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81 } |
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82 else |
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83 gripe_square_matrix_required ("inverse"); |
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84 } |
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85 else if (tmp.is_real_scalar ()) |
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86 { |
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87 double d = 1.0 / tmp.double_value (); |
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88 retval = d; |
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89 } |
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90 else if (tmp.is_complex_matrix ()) |
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91 { |
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92 ComplexMatrix m = tmp.complex_matrix_value (); |
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93 if (m.rows () == m.columns ()) |
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94 { |
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95 int info; |
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96 double rcond = 0.0; |
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97 ComplexMatrix minv = m.inverse (info, rcond); |
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98 if (info == -1) |
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99 warning ("inverse: matrix singular to machine precision,\ |
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100 rcond = %g", rcond); |
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101 else |
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102 retval = minv; |
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103 } |
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104 else |
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105 gripe_square_matrix_required ("inverse"); |
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106 } |
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107 else if (tmp.is_complex_scalar ()) |
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108 { |
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109 Complex c = 1.0 / tmp.complex_value (); |
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110 retval = c; |
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111 } |
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112 else |
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113 { |
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114 gripe_wrong_type_arg ("inv", tmp); |
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115 } |
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116 |
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117 return retval; |
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118 } |
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119 |
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120 /* |
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121 ;;; Local Variables: *** |
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122 ;;; mode: C++ *** |
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123 ;;; page-delimiter: "^/\\*" *** |
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124 ;;; End: *** |
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125 */ |
