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1 /* glpbfx.c */ |
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2 |
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3 /*********************************************************************** |
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4 * This code is part of GLPK (GNU Linear Programming Kit). |
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5 * |
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6 * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, |
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7 * 2009, 2010 Andrew Makhorin, Department for Applied Informatics, |
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8 * Moscow Aviation Institute, Moscow, Russia. All rights reserved. |
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9 * E-mail: <mao@gnu.org>. |
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10 * |
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11 * GLPK is free software: you can redistribute it and/or modify it |
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12 * under the terms of the GNU General Public License as published by |
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13 * the Free Software Foundation, either version 3 of the License, or |
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14 * (at your option) any later version. |
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15 * |
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16 * GLPK is distributed in the hope that it will be useful, but WITHOUT |
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17 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
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18 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public |
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19 * License for more details. |
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20 * |
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21 * You should have received a copy of the GNU General Public License |
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22 * along with GLPK. If not, see <http://www.gnu.org/licenses/>. |
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23 ***********************************************************************/ |
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24 |
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25 typedef struct BFX BFX; |
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26 #define GLPBFX_DEFINED |
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27 #include "glpbfx.h" |
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28 #include "glpenv.h" |
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29 #include "glplux.h" |
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30 |
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31 struct BFX |
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32 { int valid; |
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33 LUX *lux; |
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34 }; |
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35 |
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36 BFX *bfx_create_binv(void) |
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37 { /* create factorization of the basis matrix */ |
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38 BFX *bfx; |
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39 bfx = xmalloc(sizeof(BFX)); |
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40 bfx->valid = 0; |
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41 bfx->lux = NULL; |
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42 return bfx; |
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43 } |
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44 |
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45 int bfx_factorize(BFX *binv, int m, int (*col)(void *info, int j, |
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46 int ind[], mpq_t val[]), void *info) |
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47 { /* compute factorization of the basis matrix */ |
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48 int ret; |
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49 xassert(m > 0); |
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50 if (binv->lux != NULL && binv->lux->n != m) |
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51 { lux_delete(binv->lux); |
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52 binv->lux = NULL; |
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53 } |
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54 if (binv->lux == NULL) |
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55 binv->lux = lux_create(m); |
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56 ret = lux_decomp(binv->lux, col, info); |
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57 binv->valid = (ret == 0); |
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58 return ret; |
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59 } |
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60 |
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61 void bfx_ftran(BFX *binv, mpq_t x[], int save) |
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62 { /* perform forward transformation (FTRAN) */ |
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63 xassert(binv->valid); |
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64 lux_solve(binv->lux, 0, x); |
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65 xassert(save == save); |
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66 return; |
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67 } |
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68 |
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69 void bfx_btran(BFX *binv, mpq_t x[]) |
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70 { /* perform backward transformation (BTRAN) */ |
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71 xassert(binv->valid); |
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72 lux_solve(binv->lux, 1, x); |
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73 return; |
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74 } |
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75 |
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76 int bfx_update(BFX *binv, int j) |
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77 { /* update factorization of the basis matrix */ |
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78 xassert(binv->valid); |
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79 xassert(1 <= j && j <= binv->lux->n); |
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80 return 1; |
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81 } |
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82 |
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83 void bfx_delete_binv(BFX *binv) |
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84 { /* delete factorization of the basis matrix */ |
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85 if (binv->lux != NULL) |
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86 lux_delete(binv->lux); |
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87 xfree(binv); |
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88 return; |
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89 } |
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90 |
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91 /* eof */ |