| [1] | 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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