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1 // f-lu.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 "dbleLU.h" |
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29 #include "CmplxLU.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 "help.h" |
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519
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35 #include "defun-dld.h" |
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36 |
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37 DEFUN_DLD ("lu", Flu, Slu, 2, 3, |
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38 "[L, U, P] = lu (A): LU factorization") |
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39 { |
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40 Octave_object retval; |
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41 |
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42 int nargin = args.length (); |
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43 |
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44 if (nargin != 2 || nargout > 3) |
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45 { |
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46 print_usage ("lu"); |
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47 return retval; |
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48 } |
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49 |
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50 tree_constant tmp = args(1).make_numeric ();; |
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51 |
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52 if (tmp.rows () == 0 || tmp.columns () == 0) |
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53 { |
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54 int flag = user_pref.propagate_empty_matrices; |
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55 if (flag != 0) |
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56 { |
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57 if (flag < 0) |
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58 gripe_empty_arg ("lu", 0); |
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59 |
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60 retval.resize (3, Matrix ()); |
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61 return retval; |
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62 } |
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63 else |
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64 gripe_empty_arg ("lu", 1); |
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65 } |
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66 |
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67 switch (tmp.const_type ()) |
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68 { |
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69 case tree_constant_rep::matrix_constant: |
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70 { |
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71 Matrix m = tmp.matrix_value (); |
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72 if (m.rows () == m.columns ()) |
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73 { |
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74 LU fact (m); |
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75 switch (nargout) |
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76 { |
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77 case 1: |
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78 case 2: |
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79 { |
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80 Matrix P = fact.P (); |
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81 Matrix L = P.transpose () * fact.L (); |
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82 retval(1) = fact.U (); |
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83 retval(0) = L; |
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84 } |
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85 break; |
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86 case 3: |
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87 default: |
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88 retval(2) = fact.P (); |
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89 retval(1) = fact.U (); |
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90 retval(0) = fact.L (); |
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91 break; |
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92 } |
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93 } |
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94 else |
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95 gripe_square_matrix_required ("lu"); |
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96 } |
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97 break; |
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98 case tree_constant_rep::complex_matrix_constant: |
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99 { |
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100 ComplexMatrix m = tmp.complex_matrix_value (); |
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101 if (m.rows () == m.columns ()) |
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102 { |
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103 ComplexLU fact (m); |
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104 switch (nargout) |
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105 { |
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106 case 1: |
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107 case 2: |
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108 { |
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109 ComplexMatrix P = fact.P (); |
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110 ComplexMatrix L = P.transpose () * fact.L (); |
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111 retval(1) = fact.U (); |
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112 retval(0) = L; |
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113 } |
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114 break; |
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115 case 3: |
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116 default: |
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117 retval(2) = fact.P (); |
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118 retval(1) = fact.U (); |
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119 retval(0) = fact.L (); |
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120 break; |
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121 } |
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122 } |
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123 else |
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124 gripe_square_matrix_required ("lu"); |
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125 } |
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126 break; |
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127 case tree_constant_rep::scalar_constant: |
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128 { |
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129 double d = tmp.double_value (); |
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130 retval(2) = 1.0; |
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131 retval(1) = d; |
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132 retval(0) = 1.0; |
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133 } |
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134 break; |
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135 case tree_constant_rep::complex_scalar_constant: |
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136 { |
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137 Complex c = tmp.complex_value (); |
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138 retval(2) = 1.0; |
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139 retval(1) = c; |
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140 retval(0) = 1.0; |
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141 } |
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142 break; |
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143 default: |
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144 break; |
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145 } |
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146 return retval; |
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147 } |
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148 |
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149 /* |
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150 ;;; Local Variables: *** |
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151 ;;; mode: C++ *** |
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152 ;;; page-delimiter: "^/\\*" *** |
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153 ;;; End: *** |
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154 */ |
