alpar@1: /* glpbfx.c */
alpar@1: 
alpar@1: /***********************************************************************
alpar@1: *  This code is part of GLPK (GNU Linear Programming Kit).
alpar@1: *
alpar@1: *  Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
alpar@1: *  2009, 2010 Andrew Makhorin, Department for Applied Informatics,
alpar@1: *  Moscow Aviation Institute, Moscow, Russia. All rights reserved.
alpar@1: *  E-mail: <mao@gnu.org>.
alpar@1: *
alpar@1: *  GLPK is free software: you can redistribute it and/or modify it
alpar@1: *  under the terms of the GNU General Public License as published by
alpar@1: *  the Free Software Foundation, either version 3 of the License, or
alpar@1: *  (at your option) any later version.
alpar@1: *
alpar@1: *  GLPK is distributed in the hope that it will be useful, but WITHOUT
alpar@1: *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
alpar@1: *  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
alpar@1: *  License for more details.
alpar@1: *
alpar@1: *  You should have received a copy of the GNU General Public License
alpar@1: *  along with GLPK. If not, see <http://www.gnu.org/licenses/>.
alpar@1: ***********************************************************************/
alpar@1: 
alpar@1: typedef struct BFX BFX;
alpar@1: #define GLPBFX_DEFINED
alpar@1: #include "glpbfx.h"
alpar@1: #include "glpenv.h"
alpar@1: #include "glplux.h"
alpar@1: 
alpar@1: struct BFX
alpar@1: {     int valid;
alpar@1:       LUX *lux;
alpar@1: };
alpar@1: 
alpar@1: BFX *bfx_create_binv(void)
alpar@1: {     /* create factorization of the basis matrix */
alpar@1:       BFX *bfx;
alpar@1:       bfx = xmalloc(sizeof(BFX));
alpar@1:       bfx->valid = 0;
alpar@1:       bfx->lux = NULL;
alpar@1:       return bfx;
alpar@1: }
alpar@1: 
alpar@1: int bfx_factorize(BFX *binv, int m, int (*col)(void *info, int j,
alpar@1:       int ind[], mpq_t val[]), void *info)
alpar@1: {     /* compute factorization of the basis matrix */
alpar@1:       int ret;
alpar@1:       xassert(m > 0);
alpar@1:       if (binv->lux != NULL && binv->lux->n != m)
alpar@1:       {  lux_delete(binv->lux);
alpar@1:          binv->lux = NULL;
alpar@1:       }
alpar@1:       if (binv->lux == NULL)
alpar@1:          binv->lux = lux_create(m);
alpar@1:       ret = lux_decomp(binv->lux, col, info);
alpar@1:       binv->valid = (ret == 0);
alpar@1:       return ret;
alpar@1: }
alpar@1: 
alpar@1: void bfx_ftran(BFX *binv, mpq_t x[], int save)
alpar@1: {     /* perform forward transformation (FTRAN) */
alpar@1:       xassert(binv->valid);
alpar@1:       lux_solve(binv->lux, 0, x);
alpar@1:       xassert(save == save);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: void bfx_btran(BFX *binv, mpq_t x[])
alpar@1: {     /* perform backward transformation (BTRAN) */
alpar@1:       xassert(binv->valid);
alpar@1:       lux_solve(binv->lux, 1, x);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: int bfx_update(BFX *binv, int j)
alpar@1: {     /* update factorization of the basis matrix */
alpar@1:       xassert(binv->valid);
alpar@1:       xassert(1 <= j && j <= binv->lux->n);
alpar@1:       return 1;
alpar@1: }
alpar@1: 
alpar@1: void bfx_delete_binv(BFX *binv)
alpar@1: {     /* delete factorization of the basis matrix */
alpar@1:       if (binv->lux != NULL)
alpar@1:          lux_delete(binv->lux);
alpar@1:       xfree(binv);
alpar@1:       return;
alpar@1: }
alpar@1: 
alpar@1: /* eof */