diff options
Diffstat (limited to 'test/monniaux/glpk-4.65/src/api/prob5.c')
| -rw-r--r-- | test/monniaux/glpk-4.65/src/api/prob5.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/test/monniaux/glpk-4.65/src/api/prob5.c b/test/monniaux/glpk-4.65/src/api/prob5.c new file mode 100644 index 00000000..1c1d3160 --- /dev/null +++ b/test/monniaux/glpk-4.65/src/api/prob5.c @@ -0,0 +1,168 @@ +/* prob5.c (LP problem basis constructing routines) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* Copyright (C) 2000-2013 Andrew Makhorin, Department for Applied +* Informatics, Moscow Aviation Institute, Moscow, Russia. All rights +* reserved. E-mail: <mao@gnu.org>. +* +* GLPK is free software: you can redistribute it and/or modify it +* under the terms of the GNU General Public License as published by +* the Free Software Foundation, either version 3 of the License, or +* (at your option) any later version. +* +* GLPK is distributed in the hope that it will be useful, but WITHOUT +* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public +* License for more details. +* +* You should have received a copy of the GNU General Public License +* along with GLPK. If not, see <http://www.gnu.org/licenses/>. +***********************************************************************/ + +#include "env.h" +#include "prob.h" + +/*********************************************************************** +* NAME +* +* glp_set_row_stat - set (change) row status +* +* SYNOPSIS +* +* void glp_set_row_stat(glp_prob *lp, int i, int stat); +* +* DESCRIPTION +* +* The routine glp_set_row_stat sets (changes) status of the auxiliary +* variable associated with i-th row. +* +* The new status of the auxiliary variable should be specified by the +* parameter stat as follows: +* +* GLP_BS - basic variable; +* GLP_NL - non-basic variable; +* GLP_NU - non-basic variable on its upper bound; if the variable is +* not double-bounded, this means the same as GLP_NL (only in +* case of this routine); +* GLP_NF - the same as GLP_NL (only in case of this routine); +* GLP_NS - the same as GLP_NL (only in case of this routine). */ + +void glp_set_row_stat(glp_prob *lp, int i, int stat) +{ GLPROW *row; + if (!(1 <= i && i <= lp->m)) + xerror("glp_set_row_stat: i = %d; row number out of range\n", + i); + if (!(stat == GLP_BS || stat == GLP_NL || stat == GLP_NU || + stat == GLP_NF || stat == GLP_NS)) + xerror("glp_set_row_stat: i = %d; stat = %d; invalid status\n", + i, stat); + row = lp->row[i]; + if (stat != GLP_BS) + { switch (row->type) + { case GLP_FR: stat = GLP_NF; break; + case GLP_LO: stat = GLP_NL; break; + case GLP_UP: stat = GLP_NU; break; + case GLP_DB: if (stat != GLP_NU) stat = GLP_NL; break; + case GLP_FX: stat = GLP_NS; break; + default: xassert(row != row); + } + } + if (row->stat == GLP_BS && stat != GLP_BS || + row->stat != GLP_BS && stat == GLP_BS) + { /* invalidate the basis factorization */ + lp->valid = 0; + } + row->stat = stat; + return; +} + +/*********************************************************************** +* NAME +* +* glp_set_col_stat - set (change) column status +* +* SYNOPSIS +* +* void glp_set_col_stat(glp_prob *lp, int j, int stat); +* +* DESCRIPTION +* +* The routine glp_set_col_stat sets (changes) status of the structural +* variable associated with j-th column. +* +* The new status of the structural variable should be specified by the +* parameter stat as follows: +* +* GLP_BS - basic variable; +* GLP_NL - non-basic variable; +* GLP_NU - non-basic variable on its upper bound; if the variable is +* not double-bounded, this means the same as GLP_NL (only in +* case of this routine); +* GLP_NF - the same as GLP_NL (only in case of this routine); +* GLP_NS - the same as GLP_NL (only in case of this routine). */ + +void glp_set_col_stat(glp_prob *lp, int j, int stat) +{ GLPCOL *col; + if (!(1 <= j && j <= lp->n)) + xerror("glp_set_col_stat: j = %d; column number out of range\n" + , j); + if (!(stat == GLP_BS || stat == GLP_NL || stat == GLP_NU || + stat == GLP_NF || stat == GLP_NS)) + xerror("glp_set_col_stat: j = %d; stat = %d; invalid status\n", + j, stat); + col = lp->col[j]; + if (stat != GLP_BS) + { switch (col->type) + { case GLP_FR: stat = GLP_NF; break; + case GLP_LO: stat = GLP_NL; break; + case GLP_UP: stat = GLP_NU; break; + case GLP_DB: if (stat != GLP_NU) stat = GLP_NL; break; + case GLP_FX: stat = GLP_NS; break; + default: xassert(col != col); + } + } + if (col->stat == GLP_BS && stat != GLP_BS || + col->stat != GLP_BS && stat == GLP_BS) + { /* invalidate the basis factorization */ + lp->valid = 0; + } + col->stat = stat; + return; +} + +/*********************************************************************** +* NAME +* +* glp_std_basis - construct standard initial LP basis +* +* SYNOPSIS +* +* void glp_std_basis(glp_prob *lp); +* +* DESCRIPTION +* +* The routine glp_std_basis builds the "standard" (trivial) initial +* basis for the specified problem object. +* +* In the "standard" basis all auxiliary variables are basic, and all +* structural variables are non-basic. */ + +void glp_std_basis(glp_prob *lp) +{ int i, j; + /* make all auxiliary variables basic */ + for (i = 1; i <= lp->m; i++) + glp_set_row_stat(lp, i, GLP_BS); + /* make all structural variables non-basic */ + for (j = 1; j <= lp->n; j++) + { GLPCOL *col = lp->col[j]; + if (col->type == GLP_DB && fabs(col->lb) > fabs(col->ub)) + glp_set_col_stat(lp, j, GLP_NU); + else + glp_set_col_stat(lp, j, GLP_NL); + } + return; +} + +/* eof */ |