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1 // -*- C++ -*- |
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2 /* |
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3 |
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4 Copyright (C) 1992, 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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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 #if defined (__GNUG__) |
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29 #pragma implementation |
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30 #endif |
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31 |
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32 #include "dbleLU.h" |
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33 #include "mx-inlines.cc" |
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34 #include "lo-error.h" |
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35 #include "f77-uscore.h" |
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36 |
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37 extern "C" |
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38 { |
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39 int F77_FCN (dgesv) (const int*, const int*, double*, const int*, |
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40 int*, double*, const int*, int*); |
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41 } |
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42 |
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43 LU::LU (const Matrix& a) |
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44 { |
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45 int a_nr = a.rows (); |
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46 int a_nc = a.cols (); |
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47 if (a_nr == 0 || a_nc == 0 || a_nr != a_nc) |
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48 { |
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49 (*current_liboctave_error_handler) ("LU requires square matrix"); |
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50 return; |
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51 } |
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52 |
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53 int n = a_nr; |
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54 |
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55 int *ipvt = new int [n]; |
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56 int *pvt = new int [n]; |
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57 double *tmp_data = dup (a.data (), a.length ()); |
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58 int info = 0; |
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59 int zero = 0; |
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60 double b; |
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61 |
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62 F77_FCN (dgesv) (&n, &zero, tmp_data, &n, ipvt, &b, &n, &info); |
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63 |
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64 Matrix A_fact (tmp_data, n, n); |
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65 |
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66 int i; |
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67 |
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68 for (i = 0; i < n; i++) |
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69 { |
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70 ipvt[i] -= 1; |
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71 pvt[i] = i; |
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72 } |
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73 |
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74 for (i = 0; i < n - 1; i++) |
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75 { |
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76 int k = ipvt[i]; |
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77 if (k != i) |
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78 { |
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79 int tmp = pvt[k]; |
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80 pvt[k] = pvt[i]; |
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81 pvt[i] = tmp; |
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82 } |
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83 } |
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84 |
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85 l.resize (n, n, 0.0); |
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86 u.resize (n, n, 0.0); |
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87 p.resize (n, n, 0.0); |
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88 |
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89 for (i = 0; i < n; i++) |
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90 { |
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91 p.elem (i, pvt[i]) = 1.0; |
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92 |
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93 int j; |
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94 |
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95 l.elem (i, i) = 1.0; |
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96 for (j = 0; j < i; j++) |
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97 l.elem (i, j) = A_fact.elem (i, j); |
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98 |
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99 for (j = i; j < n; j++) |
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100 u.elem (i, j) = A_fact.elem (i, j); |
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101 } |
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102 |
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103 delete [] ipvt; |
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104 delete [] pvt; |
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105 } |
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106 |
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107 /* |
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108 ;;; Local Variables: *** |
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109 ;;; mode: C++ *** |
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110 ;;; page-delimiter: "^/\\*" *** |
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111 ;;; End: *** |
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112 */ |
