diff -r d59bea55db9b -r c445c931472f src/glpapi09.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/glpapi09.c Mon Dec 06 13:09:21 2010 +0100 @@ -0,0 +1,741 @@ +/* glpapi09.c (mixed integer programming routines) */ + +/*********************************************************************** +* This code is part of GLPK (GNU Linear Programming Kit). +* +* Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, +* 2009, 2010 Andrew Makhorin, Department for Applied Informatics, +* Moscow Aviation Institute, Moscow, Russia. All rights reserved. +* E-mail: . +* +* 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 . +***********************************************************************/ + +#include "glpios.h" +#include "glpnpp.h" + +/*********************************************************************** +* NAME +* +* glp_set_col_kind - set (change) column kind +* +* SYNOPSIS +* +* void glp_set_col_kind(glp_prob *mip, int j, int kind); +* +* DESCRIPTION +* +* The routine glp_set_col_kind sets (changes) the kind of j-th column +* (structural variable) as specified by the parameter kind: +* +* GLP_CV - continuous variable; +* GLP_IV - integer variable; +* GLP_BV - binary variable. */ + +void glp_set_col_kind(glp_prob *mip, int j, int kind) +{ GLPCOL *col; + if (!(1 <= j && j <= mip->n)) + xerror("glp_set_col_kind: j = %d; column number out of range\n" + , j); + col = mip->col[j]; + switch (kind) + { case GLP_CV: + col->kind = GLP_CV; + break; + case GLP_IV: + col->kind = GLP_IV; + break; + case GLP_BV: + col->kind = GLP_IV; + if (!(col->type == GLP_DB && col->lb == 0.0 && col->ub == + 1.0)) glp_set_col_bnds(mip, j, GLP_DB, 0.0, 1.0); + break; + default: + xerror("glp_set_col_kind: j = %d; kind = %d; invalid column" + " kind\n", j, kind); + } + return; +} + +/*********************************************************************** +* NAME +* +* glp_get_col_kind - retrieve column kind +* +* SYNOPSIS +* +* int glp_get_col_kind(glp_prob *mip, int j); +* +* RETURNS +* +* The routine glp_get_col_kind returns the kind of j-th column, i.e. +* the kind of corresponding structural variable, as follows: +* +* GLP_CV - continuous variable; +* GLP_IV - integer variable; +* GLP_BV - binary variable */ + +int glp_get_col_kind(glp_prob *mip, int j) +{ GLPCOL *col; + int kind; + if (!(1 <= j && j <= mip->n)) + xerror("glp_get_col_kind: j = %d; column number out of range\n" + , j); + col = mip->col[j]; + kind = col->kind; + switch (kind) + { case GLP_CV: + break; + case GLP_IV: + if (col->type == GLP_DB && col->lb == 0.0 && col->ub == 1.0) + kind = GLP_BV; + break; + default: + xassert(kind != kind); + } + return kind; +} + +/*********************************************************************** +* NAME +* +* glp_get_num_int - retrieve number of integer columns +* +* SYNOPSIS +* +* int glp_get_num_int(glp_prob *mip); +* +* RETURNS +* +* The routine glp_get_num_int returns the current number of columns, +* which are marked as integer. */ + +int glp_get_num_int(glp_prob *mip) +{ GLPCOL *col; + int j, count = 0; + for (j = 1; j <= mip->n; j++) + { col = mip->col[j]; + if (col->kind == GLP_IV) count++; + } + return count; +} + +/*********************************************************************** +* NAME +* +* glp_get_num_bin - retrieve number of binary columns +* +* SYNOPSIS +* +* int glp_get_num_bin(glp_prob *mip); +* +* RETURNS +* +* The routine glp_get_num_bin returns the current number of columns, +* which are marked as binary. */ + +int glp_get_num_bin(glp_prob *mip) +{ GLPCOL *col; + int j, count = 0; + for (j = 1; j <= mip->n; j++) + { col = mip->col[j]; + if (col->kind == GLP_IV && col->type == GLP_DB && col->lb == + 0.0 && col->ub == 1.0) count++; + } + return count; +} + +/*********************************************************************** +* NAME +* +* glp_intopt - solve MIP problem with the branch-and-bound method +* +* SYNOPSIS +* +* int glp_intopt(glp_prob *P, const glp_iocp *parm); +* +* DESCRIPTION +* +* The routine glp_intopt is a driver to the MIP solver based on the +* branch-and-bound method. +* +* On entry the problem object should contain optimal solution to LP +* relaxation (which can be obtained with the routine glp_simplex). +* +* The MIP solver has a set of control parameters. Values of the control +* parameters can be passed in a structure glp_iocp, which the parameter +* parm points to. +* +* The parameter parm can be specified as NULL, in which case the MIP +* solver uses default settings. +* +* RETURNS +* +* 0 The MIP problem instance has been successfully solved. This code +* does not necessarily mean that the solver has found optimal +* solution. It only means that the solution process was successful. +* +* GLP_EBOUND +* Unable to start the search, because some double-bounded variables +* have incorrect bounds or some integer variables have non-integer +* (fractional) bounds. +* +* GLP_EROOT +* Unable to start the search, because optimal basis for initial LP +* relaxation is not provided. +* +* GLP_EFAIL +* The search was prematurely terminated due to the solver failure. +* +* GLP_EMIPGAP +* The search was prematurely terminated, because the relative mip +* gap tolerance has been reached. +* +* GLP_ETMLIM +* The search was prematurely terminated, because the time limit has +* been exceeded. +* +* GLP_ENOPFS +* The MIP problem instance has no primal feasible solution (only if +* the MIP presolver is used). +* +* GLP_ENODFS +* LP relaxation of the MIP problem instance has no dual feasible +* solution (only if the MIP presolver is used). +* +* GLP_ESTOP +* The search was prematurely terminated by application. */ + +static int solve_mip(glp_prob *P, const glp_iocp *parm) +{ /* solve MIP directly without using the preprocessor */ + glp_tree *T; + int ret; + /* optimal basis to LP relaxation must be provided */ + if (glp_get_status(P) != GLP_OPT) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: optimal basis to initial LP relaxation" + " not provided\n"); + ret = GLP_EROOT; + goto done; + } + /* it seems all is ok */ + if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("Integer optimization begins...\n"); + /* create the branch-and-bound tree */ + T = ios_create_tree(P, parm); + /* solve the problem instance */ + ret = ios_driver(T); + /* delete the branch-and-bound tree */ + ios_delete_tree(T); + /* analyze exit code reported by the mip driver */ + if (ret == 0) + { if (P->mip_stat == GLP_FEAS) + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("INTEGER OPTIMAL SOLUTION FOUND\n"); + P->mip_stat = GLP_OPT; + } + else + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("PROBLEM HAS NO INTEGER FEASIBLE SOLUTION\n"); + P->mip_stat = GLP_NOFEAS; + } + } + else if (ret == GLP_EMIPGAP) + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("RELATIVE MIP GAP TOLERANCE REACHED; SEARCH TERMINA" + "TED\n"); + } + else if (ret == GLP_ETMLIM) + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("TIME LIMIT EXCEEDED; SEARCH TERMINATED\n"); + } + else if (ret == GLP_EFAIL) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: cannot solve current LP relaxation\n"); + } + else if (ret == GLP_ESTOP) + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("SEARCH TERMINATED BY APPLICATION\n"); + } + else + xassert(ret != ret); +done: return ret; +} + +static int preprocess_and_solve_mip(glp_prob *P, const glp_iocp *parm) +{ /* solve MIP using the preprocessor */ + ENV *env = get_env_ptr(); + int term_out = env->term_out; + NPP *npp; + glp_prob *mip = NULL; + glp_bfcp bfcp; + glp_smcp smcp; + int ret; + if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("Preprocessing...\n"); + /* create preprocessor workspace */ + npp = npp_create_wksp(); + /* load original problem into the preprocessor workspace */ + npp_load_prob(npp, P, GLP_OFF, GLP_MIP, GLP_OFF); + /* process MIP prior to applying the branch-and-bound method */ + if (!term_out || parm->msg_lev < GLP_MSG_ALL) + env->term_out = GLP_OFF; + else + env->term_out = GLP_ON; + ret = npp_integer(npp, parm); + env->term_out = term_out; + if (ret == 0) + ; + else if (ret == GLP_ENOPFS) + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("PROBLEM HAS NO PRIMAL FEASIBLE SOLUTION\n"); + } + else if (ret == GLP_ENODFS) + { if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("LP RELAXATION HAS NO DUAL FEASIBLE SOLUTION\n"); + } + else + xassert(ret != ret); + if (ret != 0) goto done; + /* build transformed MIP */ + mip = glp_create_prob(); + npp_build_prob(npp, mip); + /* if the transformed MIP is empty, it has empty solution, which + is optimal */ + if (mip->m == 0 && mip->n == 0) + { mip->mip_stat = GLP_OPT; + mip->mip_obj = mip->c0; + if (parm->msg_lev >= GLP_MSG_ALL) + { xprintf("Objective value = %17.9e\n", mip->mip_obj); + xprintf("INTEGER OPTIMAL SOLUTION FOUND BY MIP PREPROCESSOR" + "\n"); + } + goto post; + } + /* display some statistics */ + if (parm->msg_lev >= GLP_MSG_ALL) + { int ni = glp_get_num_int(mip); + int nb = glp_get_num_bin(mip); + char s[50]; + xprintf("%d row%s, %d column%s, %d non-zero%s\n", + mip->m, mip->m == 1 ? "" : "s", mip->n, mip->n == 1 ? "" : + "s", mip->nnz, mip->nnz == 1 ? "" : "s"); + if (nb == 0) + strcpy(s, "none of"); + else if (ni == 1 && nb == 1) + strcpy(s, ""); + else if (nb == 1) + strcpy(s, "one of"); + else if (nb == ni) + strcpy(s, "all of"); + else + sprintf(s, "%d of", nb); + xprintf("%d integer variable%s, %s which %s binary\n", + ni, ni == 1 ? "" : "s", s, nb == 1 ? "is" : "are"); + } + /* inherit basis factorization control parameters */ + glp_get_bfcp(P, &bfcp); + glp_set_bfcp(mip, &bfcp); + /* scale the transformed problem */ + if (!term_out || parm->msg_lev < GLP_MSG_ALL) + env->term_out = GLP_OFF; + else + env->term_out = GLP_ON; + glp_scale_prob(mip, + GLP_SF_GM | GLP_SF_EQ | GLP_SF_2N | GLP_SF_SKIP); + env->term_out = term_out; + /* build advanced initial basis */ + if (!term_out || parm->msg_lev < GLP_MSG_ALL) + env->term_out = GLP_OFF; + else + env->term_out = GLP_ON; + glp_adv_basis(mip, 0); + env->term_out = term_out; + /* solve initial LP relaxation */ + if (parm->msg_lev >= GLP_MSG_ALL) + xprintf("Solving LP relaxation...\n"); + glp_init_smcp(&smcp); + smcp.msg_lev = parm->msg_lev; + mip->it_cnt = P->it_cnt; + ret = glp_simplex(mip, &smcp); + P->it_cnt = mip->it_cnt; + if (ret != 0) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: cannot solve LP relaxation\n"); + ret = GLP_EFAIL; + goto done; + } + /* check status of the basic solution */ + ret = glp_get_status(mip); + if (ret == GLP_OPT) + ret = 0; + else if (ret == GLP_NOFEAS) + ret = GLP_ENOPFS; + else if (ret == GLP_UNBND) + ret = GLP_ENODFS; + else + xassert(ret != ret); + if (ret != 0) goto done; + /* solve the transformed MIP */ + mip->it_cnt = P->it_cnt; + ret = solve_mip(mip, parm); + P->it_cnt = mip->it_cnt; + /* only integer feasible solution can be postprocessed */ + if (!(mip->mip_stat == GLP_OPT || mip->mip_stat == GLP_FEAS)) + { P->mip_stat = mip->mip_stat; + goto done; + } + /* postprocess solution from the transformed MIP */ +post: npp_postprocess(npp, mip); + /* the transformed MIP is no longer needed */ + glp_delete_prob(mip), mip = NULL; + /* store solution to the original problem */ + npp_unload_sol(npp, P); +done: /* delete the transformed MIP, if it exists */ + if (mip != NULL) glp_delete_prob(mip); + /* delete preprocessor workspace */ + npp_delete_wksp(npp); + return ret; +} + +#ifndef HAVE_ALIEN_SOLVER /* 28/V-2010 */ +int _glp_intopt1(glp_prob *P, const glp_iocp *parm) +{ xassert(P == P); + xassert(parm == parm); + xprintf("glp_intopt: no alien solver is available\n"); + return GLP_EFAIL; +} +#endif + +int glp_intopt(glp_prob *P, const glp_iocp *parm) +{ /* solve MIP problem with the branch-and-bound method */ + glp_iocp _parm; + int i, j, ret; + /* check problem object */ + if (P == NULL || P->magic != GLP_PROB_MAGIC) + xerror("glp_intopt: P = %p; invalid problem object\n", P); + if (P->tree != NULL) + xerror("glp_intopt: operation not allowed\n"); + /* check control parameters */ + if (parm == NULL) + parm = &_parm, glp_init_iocp((glp_iocp *)parm); + if (!(parm->msg_lev == GLP_MSG_OFF || + parm->msg_lev == GLP_MSG_ERR || + parm->msg_lev == GLP_MSG_ON || + parm->msg_lev == GLP_MSG_ALL || + parm->msg_lev == GLP_MSG_DBG)) + xerror("glp_intopt: msg_lev = %d; invalid parameter\n", + parm->msg_lev); + if (!(parm->br_tech == GLP_BR_FFV || + parm->br_tech == GLP_BR_LFV || + parm->br_tech == GLP_BR_MFV || + parm->br_tech == GLP_BR_DTH || + parm->br_tech == GLP_BR_PCH)) + xerror("glp_intopt: br_tech = %d; invalid parameter\n", + parm->br_tech); + if (!(parm->bt_tech == GLP_BT_DFS || + parm->bt_tech == GLP_BT_BFS || + parm->bt_tech == GLP_BT_BLB || + parm->bt_tech == GLP_BT_BPH)) + xerror("glp_intopt: bt_tech = %d; invalid parameter\n", + parm->bt_tech); + if (!(0.0 < parm->tol_int && parm->tol_int < 1.0)) + xerror("glp_intopt: tol_int = %g; invalid parameter\n", + parm->tol_int); + if (!(0.0 < parm->tol_obj && parm->tol_obj < 1.0)) + xerror("glp_intopt: tol_obj = %g; invalid parameter\n", + parm->tol_obj); + if (parm->tm_lim < 0) + xerror("glp_intopt: tm_lim = %d; invalid parameter\n", + parm->tm_lim); + if (parm->out_frq < 0) + xerror("glp_intopt: out_frq = %d; invalid parameter\n", + parm->out_frq); + if (parm->out_dly < 0) + xerror("glp_intopt: out_dly = %d; invalid parameter\n", + parm->out_dly); + if (!(0 <= parm->cb_size && parm->cb_size <= 256)) + xerror("glp_intopt: cb_size = %d; invalid parameter\n", + parm->cb_size); + if (!(parm->pp_tech == GLP_PP_NONE || + parm->pp_tech == GLP_PP_ROOT || + parm->pp_tech == GLP_PP_ALL)) + xerror("glp_intopt: pp_tech = %d; invalid parameter\n", + parm->pp_tech); + if (parm->mip_gap < 0.0) + xerror("glp_intopt: mip_gap = %g; invalid parameter\n", + parm->mip_gap); + if (!(parm->mir_cuts == GLP_ON || parm->mir_cuts == GLP_OFF)) + xerror("glp_intopt: mir_cuts = %d; invalid parameter\n", + parm->mir_cuts); + if (!(parm->gmi_cuts == GLP_ON || parm->gmi_cuts == GLP_OFF)) + xerror("glp_intopt: gmi_cuts = %d; invalid parameter\n", + parm->gmi_cuts); + if (!(parm->cov_cuts == GLP_ON || parm->cov_cuts == GLP_OFF)) + xerror("glp_intopt: cov_cuts = %d; invalid parameter\n", + parm->cov_cuts); + if (!(parm->clq_cuts == GLP_ON || parm->clq_cuts == GLP_OFF)) + xerror("glp_intopt: clq_cuts = %d; invalid parameter\n", + parm->clq_cuts); + if (!(parm->presolve == GLP_ON || parm->presolve == GLP_OFF)) + xerror("glp_intopt: presolve = %d; invalid parameter\n", + parm->presolve); + if (!(parm->binarize == GLP_ON || parm->binarize == GLP_OFF)) + xerror("glp_intopt: binarize = %d; invalid parameter\n", + parm->binarize); + if (!(parm->fp_heur == GLP_ON || parm->fp_heur == GLP_OFF)) + xerror("glp_intopt: fp_heur = %d; invalid parameter\n", + parm->fp_heur); +#if 1 /* 28/V-2010 */ + if (!(parm->alien == GLP_ON || parm->alien == GLP_OFF)) + xerror("glp_intopt: alien = %d; invalid parameter\n", + parm->alien); +#endif + /* integer solution is currently undefined */ + P->mip_stat = GLP_UNDEF; + P->mip_obj = 0.0; + /* check bounds of double-bounded variables */ + for (i = 1; i <= P->m; i++) + { GLPROW *row = P->row[i]; + if (row->type == GLP_DB && row->lb >= row->ub) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: row %d: lb = %g, ub = %g; incorrect" + " bounds\n", i, row->lb, row->ub); + ret = GLP_EBOUND; + goto done; + } + } + for (j = 1; j <= P->n; j++) + { GLPCOL *col = P->col[j]; + if (col->type == GLP_DB && col->lb >= col->ub) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: column %d: lb = %g, ub = %g; incorr" + "ect bounds\n", j, col->lb, col->ub); + ret = GLP_EBOUND; + goto done; + } + } + /* bounds of all integer variables must be integral */ + for (j = 1; j <= P->n; j++) + { GLPCOL *col = P->col[j]; + if (col->kind != GLP_IV) continue; + if (col->type == GLP_LO || col->type == GLP_DB) + { if (col->lb != floor(col->lb)) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: integer column %d has non-intege" + "r lower bound %g\n", j, col->lb); + ret = GLP_EBOUND; + goto done; + } + } + if (col->type == GLP_UP || col->type == GLP_DB) + { if (col->ub != floor(col->ub)) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: integer column %d has non-intege" + "r upper bound %g\n", j, col->ub); + ret = GLP_EBOUND; + goto done; + } + } + if (col->type == GLP_FX) + { if (col->lb != floor(col->lb)) + { if (parm->msg_lev >= GLP_MSG_ERR) + xprintf("glp_intopt: integer column %d has non-intege" + "r fixed value %g\n", j, col->lb); + ret = GLP_EBOUND; + goto done; + } + } + } + /* solve MIP problem */ + if (parm->msg_lev >= GLP_MSG_ALL) + { int ni = glp_get_num_int(P); + int nb = glp_get_num_bin(P); + char s[50]; + xprintf("GLPK Integer Optimizer, v%s\n", glp_version()); + xprintf("%d row%s, %d column%s, %d non-zero%s\n", + P->m, P->m == 1 ? "" : "s", P->n, P->n == 1 ? "" : "s", + P->nnz, P->nnz == 1 ? "" : "s"); + if (nb == 0) + strcpy(s, "none of"); + else if (ni == 1 && nb == 1) + strcpy(s, ""); + else if (nb == 1) + strcpy(s, "one of"); + else if (nb == ni) + strcpy(s, "all of"); + else + sprintf(s, "%d of", nb); + xprintf("%d integer variable%s, %s which %s binary\n", + ni, ni == 1 ? "" : "s", s, nb == 1 ? "is" : "are"); + } +#if 1 /* 28/V-2010 */ + if (parm->alien) + { /* use alien integer optimizer */ + ret = _glp_intopt1(P, parm); + goto done; + } +#endif + if (!parm->presolve) + ret = solve_mip(P, parm); + else + ret = preprocess_and_solve_mip(P, parm); +done: /* return to the application program */ + return ret; +} + +/*********************************************************************** +* NAME +* +* glp_init_iocp - initialize integer optimizer control parameters +* +* SYNOPSIS +* +* void glp_init_iocp(glp_iocp *parm); +* +* DESCRIPTION +* +* The routine glp_init_iocp initializes control parameters, which are +* used by the integer optimizer, with default values. +* +* Default values of the control parameters are stored in a glp_iocp +* structure, which the parameter parm points to. */ + +void glp_init_iocp(glp_iocp *parm) +{ parm->msg_lev = GLP_MSG_ALL; + parm->br_tech = GLP_BR_DTH; + parm->bt_tech = GLP_BT_BLB; + parm->tol_int = 1e-5; + parm->tol_obj = 1e-7; + parm->tm_lim = INT_MAX; + parm->out_frq = 5000; + parm->out_dly = 10000; + parm->cb_func = NULL; + parm->cb_info = NULL; + parm->cb_size = 0; + parm->pp_tech = GLP_PP_ALL; + parm->mip_gap = 0.0; + parm->mir_cuts = GLP_OFF; + parm->gmi_cuts = GLP_OFF; + parm->cov_cuts = GLP_OFF; + parm->clq_cuts = GLP_OFF; + parm->presolve = GLP_OFF; + parm->binarize = GLP_OFF; + parm->fp_heur = GLP_OFF; +#if 1 /* 28/V-2010 */ + parm->alien = GLP_OFF; +#endif + return; +} + +/*********************************************************************** +* NAME +* +* glp_mip_status - retrieve status of MIP solution +* +* SYNOPSIS +* +* int glp_mip_status(glp_prob *mip); +* +* RETURNS +* +* The routine lpx_mip_status reports the status of MIP solution found +* by the branch-and-bound solver as follows: +* +* GLP_UNDEF - MIP solution is undefined; +* GLP_OPT - MIP solution is integer optimal; +* GLP_FEAS - MIP solution is integer feasible but its optimality +* (or non-optimality) has not been proven, perhaps due to +* premature termination of the search; +* GLP_NOFEAS - problem has no integer feasible solution (proven by the +* solver). */ + +int glp_mip_status(glp_prob *mip) +{ int mip_stat = mip->mip_stat; + return mip_stat; +} + +/*********************************************************************** +* NAME +* +* glp_mip_obj_val - retrieve objective value (MIP solution) +* +* SYNOPSIS +* +* double glp_mip_obj_val(glp_prob *mip); +* +* RETURNS +* +* The routine glp_mip_obj_val returns value of the objective function +* for MIP solution. */ + +double glp_mip_obj_val(glp_prob *mip) +{ /*struct LPXCPS *cps = mip->cps;*/ + double z; + z = mip->mip_obj; + /*if (cps->round && fabs(z) < 1e-9) z = 0.0;*/ + return z; +} + +/*********************************************************************** +* NAME +* +* glp_mip_row_val - retrieve row value (MIP solution) +* +* SYNOPSIS +* +* double glp_mip_row_val(glp_prob *mip, int i); +* +* RETURNS +* +* The routine glp_mip_row_val returns value of the auxiliary variable +* associated with i-th row. */ + +double glp_mip_row_val(glp_prob *mip, int i) +{ /*struct LPXCPS *cps = mip->cps;*/ + double mipx; + if (!(1 <= i && i <= mip->m)) + xerror("glp_mip_row_val: i = %d; row number out of range\n", i) + ; + mipx = mip->row[i]->mipx; + /*if (cps->round && fabs(mipx) < 1e-9) mipx = 0.0;*/ + return mipx; +} + +/*********************************************************************** +* NAME +* +* glp_mip_col_val - retrieve column value (MIP solution) +* +* SYNOPSIS +* +* double glp_mip_col_val(glp_prob *mip, int j); +* +* RETURNS +* +* The routine glp_mip_col_val returns value of the structural variable +* associated with j-th column. */ + +double glp_mip_col_val(glp_prob *mip, int j) +{ /*struct LPXCPS *cps = mip->cps;*/ + double mipx; + if (!(1 <= j && j <= mip->n)) + xerror("glp_mip_col_val: j = %d; column number out of range\n", + j); + mipx = mip->col[j]->mipx; + /*if (cps->round && fabs(mipx) < 1e-9) mipx = 0.0;*/ + return mipx; +} + +/* eof */