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 */ |
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