void NUMlinprog_run (NUMlinprog me) { try { glp_smcp parm; glp_init_smcp (& parm); parm. msg_lev = GLP_MSG_OFF; my status = glp_simplex (my linearProgram, & parm); switch (my status) { case GLP_EBADB: Melder_throw (U"Unable to start the search, because the initial basis is invalid."); case GLP_ESING: Melder_throw (U"Unable to start the search, because the basis matrix is singular."); case GLP_ECOND: Melder_throw (U"Unable to start the search, because the basis matrix is ill-conditioned."); case GLP_EBOUND: Melder_throw (U"Unable to start the search, because some variables have incorrect bounds."); case GLP_EFAIL: Melder_throw (U"Search prematurely terminated due to solver failure."); case GLP_EOBJLL: Melder_throw (U"Search prematurely terminated: lower limit reached."); case GLP_EOBJUL: Melder_throw (U"Search prematurely terminated: upper limit reached."); case GLP_EITLIM: Melder_throw (U"Search prematurely terminated: iteration limit exceeded."); case GLP_ETMLIM: Melder_throw (U"Search prematurely terminated: time limit exceeded."); case GLP_ENOPFS: Melder_throw (U"The problem has no primal feasible solution."); case GLP_ENODFS: Melder_throw (U"The problem has no dual feasible solution."); default: break; } my status = glp_get_status (my linearProgram); switch (my status) { case GLP_INFEAS: Melder_throw (U"Solution is infeasible."); case GLP_NOFEAS: Melder_throw (U"Problem has no feasible solution."); case GLP_UNBND: Melder_throw (U"Problem has unbounded solution."); case GLP_UNDEF: Melder_throw (U"Solution is undefined."); default: break; } if (my status == GLP_FEAS) { Melder_warning (U"Linear programming solution is feasible but not optimal."); } } catch (MelderError) { Melder_throw (U"Linear programming: not run."); } }
void B2GlpkHasher::build_hash() { glp_simplex(_lp, NULL); glp_iocp parm; glp_init_iocp(&parm); parm.presolve = GLP_ON; parm.binarize = GLP_ON; glp_intopt(_lp, &parm); double motif_count = glp_mip_obj_val(_lp); if((motif_count > 0) && (motif_count <= (_str_set.size() * 2))) { _motif_set = _trace_set; B2HashMap<B2Trace, unsigned int> &trace_vals = _motif_set.trace_vals(); for(B2HashMap<B2Trace, unsigned int>::iterator trace_it = trace_vals.begin(); trace_it != trace_vals.end(); ) { double is_motif = glp_mip_col_val(_lp, trace_it->second); if(is_motif == 0) { _motif_set.erase(trace_it->first); B2_HASH_MAP_ERASE(trace_vals, trace_it); } else { ++trace_it; }; }; } else { b2_preproc_error_inc(B2_PREPROC_ERROR_BAD_MOTIF_SET, 1); }; };
void printResult(glp_prob * Prob, FILE * out) { int i; char buf[AUXSIZE]; glp_smcp * param = malloc(sizeof(glp_smcp)); glp_init_smcp(param); param->msg_lev = GLP_MSG_ERR; param->presolve = GLP_ON; int solution[MAXSIZE]; for( i = 0 ; i < n ; ++i ) solution[planes[i].pos] = i; mapSolution(Prob,solution); glp_simplex(Prob,param); if( simpleOutput ) { time(&final); fprintf(out,"%i & %i \\\\ \n",(int)glp_get_obj_val(Prob),(int)difftime(final,initial)); return; } fprintf(out,"Best found solution's value: %lf\n\n",glp_get_obj_val(Prob)); double time; for( i = 0 ; i < n ; ++i ) { sprintf(buf,"x%i",solution[i]); time = glp_get_col_prim(Prob, glp_find_col(Prob, buf)); fprintf(out,"The %i-th airplane to arrive is airplane %i, at the time %lf\n", i+1,solution[i]+1,time); } }
int main(void) { glp_prob *mip; glp_tran *tran; int ret; mip = glp_create_prob(); tran = glp_mpl_alloc_wksp(); ret = glp_mpl_read_model(tran, "sudoku.mod", 1); if (ret != 0) { fprintf(stderr, "Error on translating model\n"); goto skip; } ret = glp_mpl_read_data(tran, "sudoku.dat"); if (ret != 0) { fprintf(stderr, "Error on translating data\n"); goto skip; } ret = glp_mpl_generate(tran, NULL); if (ret != 0) { fprintf(stderr, "Error on generating model\n"); goto skip; } glp_mpl_build_prob(tran, mip); glp_simplex(mip, NULL); glp_intopt(mip, NULL); ret = glp_mpl_postsolve(tran, mip, GLP_MPL_MIP); if (ret != 0) fprintf(stderr, "Error on postsolving model\n"); skip: glp_mpl_free_wksp(tran); glp_delete_prob(mip); return 0; }
int c_glp_solve_simplex(glp_prob *lp, int msg_lev, int tm_lim, int presolve){ glp_smcp smcp; glp_init_smcp (&smcp); smcp.msg_lev = msg_lev; smcp.tm_lim = tm_lim; smcp.presolve = presolve ? GLP_ON : GLP_OFF; glp_adv_basis(lp, 0); return glp_simplex(lp, &smcp); }
int main(void) { glp_prob *P; P = glp_create_prob(); glp_read_mps(P, GLP_MPS_DECK, NULL, "25fv47.mps"); glp_adv_basis(P, 0); glp_simplex(P, NULL); glp_print_sol(P, "25fv47.txt"); glp_delete_prob(P); return 0; }
double solve() { glp_smcp smcp; glp_iocp iocp; glp_init_smcp(&smcp); smcp.msg_lev = GLP_MSG_ERR; glp_init_iocp(&iocp); iocp.msg_lev = GLP_MSG_ERR; glp_load_matrix(ip_, ia_.size()-1, &ia_[0], &ja_[0], &ar_[0]); glp_simplex(ip_, &smcp); glp_intopt(ip_, &iocp); return glp_mip_obj_val(ip_); }
int main(void) { glp_prob *P; glp_smcp parm; P = glp_create_prob(); glp_read_mps(P, GLP_MPS_DECK, NULL, "25fv47.mps"); glp_init_smcp(&parm); parm.meth = GLP_DUAL; glp_simplex(P, &parm); glp_print_sol(P, "25fv47.txt"); glp_delete_prob(P); return 0; }
/* call the LP solver; mult is either +1.0 or -1.0 */ static char *invoke_lp(void) {int glp_res; glp_res=glp_simplex(P,&parm); switch(glp_res){ case 0: glp_res=glp_get_status(P); break; case GLP_ENOPFS: // no primal feasible solution glp_res=GLP_NOFEAS; break; default: return glp_return_msg(glp_res); } return (glp_res==GLP_OPT ? EXPR_TRUE : glp_res==GLP_NOFEAS ? EXPR_FALSE : glp_status_msg(glp_res)); }
int main(void) { glp_prob *lp; int ia[1+1000], ja[1+1000]; double ar[1+1000], z, x1, x2, x3; s1: lp = glp_create_prob(); s2: glp_set_prob_name(lp, "sample"); s3: glp_set_obj_dir(lp, GLP_MAX); s4: glp_add_rows(lp, 3); s5: glp_set_row_name(lp, 1, "p"); s6: glp_set_row_bnds(lp, 1, GLP_UP, 0.0, 100.0); s7: glp_set_row_name(lp, 2, "q"); s8: glp_set_row_bnds(lp, 2, GLP_UP, 0.0, 600.0); s9: glp_set_row_name(lp, 3, "r"); s10: glp_set_row_bnds(lp, 3, GLP_UP, 0.0, 300.0); s11: glp_add_cols(lp, 3); s12: glp_set_col_name(lp, 1, "x1"); s13: glp_set_col_bnds(lp, 1, GLP_LO, 0.0, 0.0); s14: glp_set_obj_coef(lp, 1, 10.0); s15: glp_set_col_name(lp, 2, "x2"); s16: glp_set_col_bnds(lp, 2, GLP_LO, 0.0, 0.0); s17: glp_set_obj_coef(lp, 2, 6.0); s18: glp_set_col_name(lp, 3, "x3"); s19: glp_set_col_bnds(lp, 3, GLP_LO, 0.0, 0.0); s20: glp_set_obj_coef(lp, 3, 4.0); s21: ia[1] = 1, ja[1] = 1, ar[1] = 1.0; /* a[1,1] = 1 */ s22: ia[2] = 1, ja[2] = 2, ar[2] = 1.0; /* a[1,2] = 1 */ s23: ia[3] = 1, ja[3] = 3, ar[3] = 1.0; /* a[1,3] = 1 */ s24: ia[4] = 2, ja[4] = 1, ar[4] = 10.0; /* a[2,1] = 10 */ s25: ia[5] = 3, ja[5] = 1, ar[5] = 2.0; /* a[3,1] = 2 */ s26: ia[6] = 2, ja[6] = 2, ar[6] = 4.0; /* a[2,2] = 4 */ s27: ia[7] = 3, ja[7] = 2, ar[7] = 2.0; /* a[3,2] = 2 */ s28: ia[8] = 2, ja[8] = 3, ar[8] = 5.0; /* a[2,3] = 5 */ s29: ia[9] = 3, ja[9] = 3, ar[9] = 6.0; /* a[3,3] = 6 */ s30: glp_load_matrix(lp, 9, ia, ja, ar); s31: glp_simplex(lp, NULL); s32: z = glp_get_obj_val(lp); s33: x1 = glp_get_col_prim(lp, 1); s34: x2 = glp_get_col_prim(lp, 2); s35: x3 = glp_get_col_prim(lp, 3); s36: printf("\nz = %g; x1 = %g; x2 = %g; x3 = %g\n", z, x1, x2, x3); s37: glp_delete_prob(lp); return 0; }
/* Different cases : * - if the created node is root, then father is NULL, the problem version in the node is the one gave as parameter. * - else we copy the problem, and had the constraint "x_{y} = valy" */ void create_node(node* n, glp_prob* prob, node* father, int y, double valy) { n->father = father; n->leftSon = NULL; n->rightSon = NULL; n->check = 0; int i = 0; int ind[] = {0,y}; double val[] = {0,1}; if (n-> father == NULL) { n->prob = prob; } else { n->prob = glp_create_prob(); glp_copy_prob(n->prob, n->father->prob, GLP_ON); i = glp_add_rows(n->prob, 1); glp_set_mat_row(n->prob, i, 1, ind, val); glp_set_row_bnds(n->prob, i, GLP_FX, valy, valy); } glp_smcp parm; glp_init_smcp(&parm); parm.msg_lev = GLP_MSG_OFF; glp_iocp parmip; glp_init_iocp(&parmip); parmip.msg_lev = GLP_MSG_OFF; glp_write_lp(prob, NULL, "ULS.lp"); n->solveFlag = glp_simplex(n->prob, &parm); glp_intopt(n->prob, &parmip); n->z = glp_mip_obj_val(n->prob); n->x = (double *) malloc (glp_get_num_cols(n->prob) * sizeof(double)); for (i = 0; i < glp_get_num_cols(n->prob); ++i) n->x[i] = glp_mip_col_val(n->prob, i+1); }
int lpx_simplex(LPX *lp) { /* easy-to-use driver to the simplex method */ glp_smcp parm; int ret; fill_smcp(lp, &parm); ret = glp_simplex(lp, &parm); switch (ret) { case 0: ret = LPX_E_OK; break; case GLP_EBADB: case GLP_ESING: case GLP_ECOND: case GLP_EBOUND: ret = LPX_E_FAULT; break; case GLP_EFAIL: ret = LPX_E_SING; break; case GLP_EOBJLL: ret = LPX_E_OBJLL; break; case GLP_EOBJUL: ret = LPX_E_OBJUL; break; case GLP_EITLIM: ret = LPX_E_ITLIM; break; case GLP_ETMLIM: ret = LPX_E_TMLIM; break; case GLP_ENOPFS: ret = LPX_E_NOPFS; break; case GLP_ENODFS: ret = LPX_E_NODFS; break; default: xassert(ret != ret); } return ret; }
int max_flow_lp(int nn, int ne, const int beg[/*1+ne*/], const int end[/*1+ne*/], const int cap[/*1+ne*/], int s, int t, int x[/*1+ne*/]) { glp_prob *lp; glp_smcp smcp; int i, k, nz, flow, *rn, *cn; double temp, *aa; /* create LP problem instance */ lp = glp_create_prob(); /* create LP rows; i-th row is the conservation condition of the * flow at i-th node, i = 1, ..., nn */ glp_add_rows(lp, nn); for (i = 1; i <= nn; i++) glp_set_row_bnds(lp, i, GLP_FX, 0.0, 0.0); /* create LP columns; k-th column is the elementary flow thru * k-th edge, k = 1, ..., ne; the last column with the number * ne+1 is the total flow through the network, which goes along * a dummy feedback edge from the sink to the source */ glp_add_cols(lp, ne+1); for (k = 1; k <= ne; k++) { xassert(cap[k] > 0); glp_set_col_bnds(lp, k, GLP_DB, -cap[k], +cap[k]); } glp_set_col_bnds(lp, ne+1, GLP_FR, 0.0, 0.0); /* build the constraint matrix; structurally this matrix is the * incidence matrix of the network, so each its column (including * the last column for the dummy edge) has exactly two non-zero * entries */ rn = xalloc(1+2*(ne+1), sizeof(int)); cn = xalloc(1+2*(ne+1), sizeof(int)); aa = xalloc(1+2*(ne+1), sizeof(double)); nz = 0; for (k = 1; k <= ne; k++) { /* x[k] > 0 means the elementary flow thru k-th edge goes from * node beg[k] to node end[k] */ nz++, rn[nz] = beg[k], cn[nz] = k, aa[nz] = -1.0; nz++, rn[nz] = end[k], cn[nz] = k, aa[nz] = +1.0; } /* total flow thru the network goes from the sink to the source * along the dummy feedback edge */ nz++, rn[nz] = t, cn[nz] = ne+1, aa[nz] = -1.0; nz++, rn[nz] = s, cn[nz] = ne+1, aa[nz] = +1.0; /* check the number of non-zero entries */ xassert(nz == 2*(ne+1)); /* load the constraint matrix into the LP problem object */ glp_load_matrix(lp, nz, rn, cn, aa); xfree(rn); xfree(cn); xfree(aa); /* objective function is the total flow through the network to * be maximized */ glp_set_obj_dir(lp, GLP_MAX); glp_set_obj_coef(lp, ne + 1, 1.0); /* solve LP instance with the (primal) simplex method */ glp_term_out(0); glp_adv_basis(lp, 0); glp_term_out(1); glp_init_smcp(&smcp); smcp.msg_lev = GLP_MSG_ON; smcp.out_dly = 5000; xassert(glp_simplex(lp, &smcp) == 0); xassert(glp_get_status(lp) == GLP_OPT); /* obtain optimal elementary flows thru edges of the network */ /* (note that the constraint matrix is unimodular and the data * are integral, so all elementary flows in basic solution should * also be integral) */ for (k = 1; k <= ne; k++) { temp = glp_get_col_prim(lp, k); x[k] = (int)floor(temp + .5); xassert(fabs(x[k] - temp) <= 1e-6); } /* obtain the maximum flow thru the original network which is the * flow thru the dummy feedback edge */ temp = glp_get_col_prim(lp, ne+1); flow = (int)floor(temp + .5); xassert(fabs(flow - temp) <= 1e-6); /* delete LP problem instance */ glp_delete_prob(lp); /* return to the calling program */ return flow; }
void ios_feas_pump(glp_tree *T) { glp_prob *P = T->mip; int n = P->n; glp_prob *lp = NULL; struct VAR *var = NULL; RNG *rand = NULL; GLPCOL *col; glp_smcp parm; int j, k, new_x, nfail, npass, nv, ret, stalling; double dist, tol; xassert(glp_get_status(P) == GLP_OPT); /* this heuristic is applied only once on the root level */ if (!(T->curr->level == 0 && T->curr->solved == 1)) goto done; /* determine number of binary variables */ nv = 0; for (j = 1; j <= n; j++) { col = P->col[j]; /* if x[j] is continuous, skip it */ if (col->kind == GLP_CV) continue; /* if x[j] is fixed, skip it */ if (col->type == GLP_FX) continue; /* x[j] is non-fixed integer */ xassert(col->kind == GLP_IV); if (col->type == GLP_DB && col->lb == 0.0 && col->ub == 1.0) { /* x[j] is binary */ nv++; } else { /* x[j] is general integer */ if (T->parm->msg_lev >= GLP_MSG_ALL) xprintf("FPUMP heuristic cannot be applied due to genera" "l integer variables\n"); goto done; } } /* there must be at least one binary variable */ if (nv == 0) goto done; if (T->parm->msg_lev >= GLP_MSG_ALL) xprintf("Applying FPUMP heuristic...\n"); /* build the list of binary variables */ var = xcalloc(1+nv, sizeof(struct VAR)); k = 0; for (j = 1; j <= n; j++) { col = P->col[j]; if (col->kind == GLP_IV && col->type == GLP_DB) var[++k].j = j; } xassert(k == nv); /* create working problem object */ lp = glp_create_prob(); more: /* copy the original problem object to keep it intact */ glp_copy_prob(lp, P, GLP_OFF); /* we are interested to find an integer feasible solution, which is better than the best known one */ if (P->mip_stat == GLP_FEAS) { int *ind; double *val, bnd; /* add a row and make it identical to the objective row */ glp_add_rows(lp, 1); ind = xcalloc(1+n, sizeof(int)); val = xcalloc(1+n, sizeof(double)); for (j = 1; j <= n; j++) { ind[j] = j; val[j] = P->col[j]->coef; } glp_set_mat_row(lp, lp->m, n, ind, val); xfree(ind); xfree(val); /* introduce upper (minimization) or lower (maximization) bound to the original objective function; note that this additional constraint is not violated at the optimal point to LP relaxation */ #if 0 /* modified by xypron <*****@*****.**> */ if (P->dir == GLP_MIN) { bnd = P->mip_obj - 0.10 * (1.0 + fabs(P->mip_obj)); if (bnd < P->obj_val) bnd = P->obj_val; glp_set_row_bnds(lp, lp->m, GLP_UP, 0.0, bnd - P->c0); } else if (P->dir == GLP_MAX) { bnd = P->mip_obj + 0.10 * (1.0 + fabs(P->mip_obj)); if (bnd > P->obj_val) bnd = P->obj_val; glp_set_row_bnds(lp, lp->m, GLP_LO, bnd - P->c0, 0.0); } else xassert(P != P); #else bnd = 0.1 * P->obj_val + 0.9 * P->mip_obj; /* xprintf("bnd = %f\n", bnd); */ if (P->dir == GLP_MIN) glp_set_row_bnds(lp, lp->m, GLP_UP, 0.0, bnd - P->c0); else if (P->dir == GLP_MAX) glp_set_row_bnds(lp, lp->m, GLP_LO, bnd - P->c0, 0.0); else xassert(P != P); #endif } /* reset pass count */ npass = 0; /* invalidate the rounded point */ for (k = 1; k <= nv; k++) var[k].x = -1; pass: /* next pass starts here */ npass++; if (T->parm->msg_lev >= GLP_MSG_ALL) xprintf("Pass %d\n", npass); /* initialize minimal distance between the basic point and the rounded one obtained during this pass */ dist = DBL_MAX; /* reset failure count (the number of succeeded iterations failed to improve the distance) */ nfail = 0; /* if it is not the first pass, perturb the last rounded point rather than construct it from the basic solution */ if (npass > 1) { double rho, temp; if (rand == NULL) rand = rng_create_rand(); for (k = 1; k <= nv; k++) { j = var[k].j; col = lp->col[j]; rho = rng_uniform(rand, -0.3, 0.7); if (rho < 0.0) rho = 0.0; temp = fabs((double)var[k].x - col->prim); if (temp + rho > 0.5) var[k].x = 1 - var[k].x; } goto skip; } loop: /* innermost loop begins here */ /* round basic solution (which is assumed primal feasible) */ stalling = 1; for (k = 1; k <= nv; k++) { col = lp->col[var[k].j]; if (col->prim < 0.5) { /* rounded value is 0 */ new_x = 0; } else { /* rounded value is 1 */ new_x = 1; } if (var[k].x != new_x) { stalling = 0; var[k].x = new_x; } } /* if the rounded point has not changed (stalling), choose and flip some its entries heuristically */ if (stalling) { /* compute d[j] = |x[j] - round(x[j])| */ for (k = 1; k <= nv; k++) { col = lp->col[var[k].j]; var[k].d = fabs(col->prim - (double)var[k].x); } /* sort the list of binary variables by descending d[j] */ qsort(&var[1], nv, sizeof(struct VAR), fcmp); /* choose and flip some rounded components */ for (k = 1; k <= nv; k++) { if (k >= 5 && var[k].d < 0.35 || k >= 10) break; var[k].x = 1 - var[k].x; } } skip: /* check if the time limit has been exhausted */ if (T->parm->tm_lim < INT_MAX && (double)(T->parm->tm_lim - 1) <= 1000.0 * xdifftime(xtime(), T->tm_beg)) goto done; /* build the objective, which is the distance between the current (basic) point and the rounded one */ lp->dir = GLP_MIN; lp->c0 = 0.0; for (j = 1; j <= n; j++) lp->col[j]->coef = 0.0; for (k = 1; k <= nv; k++) { j = var[k].j; if (var[k].x == 0) lp->col[j]->coef = +1.0; else { lp->col[j]->coef = -1.0; lp->c0 += 1.0; } } /* minimize the distance with the simplex method */ glp_init_smcp(&parm); if (T->parm->msg_lev <= GLP_MSG_ERR) parm.msg_lev = T->parm->msg_lev; else if (T->parm->msg_lev <= GLP_MSG_ALL) { parm.msg_lev = GLP_MSG_ON; parm.out_dly = 10000; } ret = glp_simplex(lp, &parm); if (ret != 0) { if (T->parm->msg_lev >= GLP_MSG_ERR) xprintf("Warning: glp_simplex returned %d\n", ret); goto done; } ret = glp_get_status(lp); if (ret != GLP_OPT) { if (T->parm->msg_lev >= GLP_MSG_ERR) xprintf("Warning: glp_get_status returned %d\n", ret); goto done; } if (T->parm->msg_lev >= GLP_MSG_DBG) xprintf("delta = %g\n", lp->obj_val); /* check if the basic solution is integer feasible; note that it may be so even if the minimial distance is positive */ tol = 0.3 * T->parm->tol_int; for (k = 1; k <= nv; k++) { col = lp->col[var[k].j]; if (tol < col->prim && col->prim < 1.0 - tol) break; } if (k > nv) { /* okay; the basic solution seems to be integer feasible */ double *x = xcalloc(1+n, sizeof(double)); for (j = 1; j <= n; j++) { x[j] = lp->col[j]->prim; if (P->col[j]->kind == GLP_IV) x[j] = floor(x[j] + 0.5); } #if 1 /* modified by xypron <*****@*****.**> */ /* reset direction and right-hand side of objective */ lp->c0 = P->c0; lp->dir = P->dir; /* fix integer variables */ for (k = 1; k <= nv; k++) #if 0 /* 18/VI-2013; fixed by mao * this bug causes numerical instability, because column statuses * are not changed appropriately */ { lp->col[var[k].j]->lb = x[var[k].j]; lp->col[var[k].j]->ub = x[var[k].j]; lp->col[var[k].j]->type = GLP_FX; } #else glp_set_col_bnds(lp, var[k].j, GLP_FX, x[var[k].j], 0.); #endif /* copy original objective function */ for (j = 1; j <= n; j++) lp->col[j]->coef = P->col[j]->coef; /* solve original LP and copy result */ ret = glp_simplex(lp, &parm); if (ret != 0) { if (T->parm->msg_lev >= GLP_MSG_ERR) xprintf("Warning: glp_simplex returned %d\n", ret); goto done; } ret = glp_get_status(lp); if (ret != GLP_OPT) { if (T->parm->msg_lev >= GLP_MSG_ERR) xprintf("Warning: glp_get_status returned %d\n", ret); goto done; } for (j = 1; j <= n; j++) if (P->col[j]->kind != GLP_IV) x[j] = lp->col[j]->prim; #endif ret = glp_ios_heur_sol(T, x); xfree(x); if (ret == 0) { /* the integer solution is accepted */ if (ios_is_hopeful(T, T->curr->bound)) { /* it is reasonable to apply the heuristic once again */ goto more; } else { /* the best known integer feasible solution just found is close to optimal solution to LP relaxation */ goto done; } } }
int main(int argc, char *argv[]) { /* Structures de données propres à GLPK */ glp_prob *prob; // Déclaration d'un pointeur sur le problème int ia[1 + NBCREUX]; int ja[1 + NBCREUX]; double ar[1 + NBCREUX]; // Déclaration des 3 tableaux servant à définir la partie creuse de la matrice des contraintes /* Variables récupérant les résultats de la résolution du problème (fonction objectif et valeur des variables) */ int i, j; double z; double x[NBVAR]; // Autres variables int * p = (int*)malloc(n * sizeof(int)); p[1] = 34; p[2] = 6; p[3] = 8; p[4] = 17; p[5] = 16; p[6] = 5; p[7] = 13; p[8] = 21; p[9] = 25; p[10] = 31; p[11] = 14; p[12] = 13; p[13] = 33; p[14] = 9; p[15] = 25; p[16] = 25; /* Transfert de ces données dans les structures utilisées par la bibliothèque GLPK */ prob = glp_create_prob(); /* allocation mémoire pour le problème */ glp_set_prob_name(prob, "wagons"); /* affectation d'un nom */ glp_set_obj_dir(prob, GLP_MIN); /* Il s'agit d'un problème de minimisation */ /* Déclaration du nombre de contraintes (nombre de lignes de la matrice des contraintes) */ glp_add_rows(prob, NBCONTR); /* On commence par préciser les bornes sur les contraintes, les indices commencent à 1 (!) dans GLPK */ /* Premier ensemble de contraintes ( c = 1 ) */ for(i = 1; i <= n; i++) { glp_set_row_bnds(prob, i, GLP_FX, 1.0, 1.0); } /* Second ensembles de contraintes (c <= 0 ) */ for(i = n + 1; i <= NBCONTR; i++) { glp_set_row_bnds(prob, i, GLP_UP, 0.0, 0.0); } /* Déclaration du nombre de variables */ glp_add_cols(prob, NBVAR); /* On précise le type des variables, les indices commencent à 1 également pour les variables! */ for(i = 1; i <= NBVAR - 1; i++) { glp_set_col_bnds(prob, i, GLP_DB, 0.0, 1.0); glp_set_col_kind(prob, i, GLP_BV); /* les variables sont binaires */ } glp_set_col_bnds(prob, NBVAR, GLP_LO, 0.0, 0.0); /* La dernière variables est continue (par défaut) non négative */ /* Définition des coefficients des variables dans la fonction objectif */ for(i = 1;i <= n*m;i++) { glp_set_obj_coef(prob,i,0.0); // Tous les coûts sont à 0 (sauf le dernier) } /* Dernier coût (qui vaut 1) */ glp_set_obj_coef(prob,n*m + 1,1.0); /* Définition des coefficients non-nuls dans la matrice des contraintes, autrement dit les coefficients de la matrice creuse */ int pos = 1; for(i = 1; i <= n; i++) { for(j = 1; j <= m; j++) { // Première moitié de la matrice ja[pos] = (i - 1)*m + j; ia[pos] = i; ar[pos] = 1; pos++; // Deuxième moitié de la matrice ja[pos] = (i - 1)*m + j; ia[pos] = n + j; ar[pos] = p[i]; pos++; } } // ajout des -1 dans la dernière colonne for(i = n + 1; i <= n + m; i++) { ja[pos] = n*m + 1; ia[pos] = i; ar[pos] = -1; pos++; } /* Chargement de la matrice dans le problème */ glp_load_matrix(prob,NBCREUX,ia,ja,ar); /* Ecriture de la modélisation dans un fichier */ glp_write_lp(prob,NULL,"wagons.lp"); /* Résolution, puis lecture des résultats */ glp_simplex(prob,NULL); glp_intopt(prob,NULL); /* Résolution */ z = glp_mip_obj_val(prob); /* Récupération de la valeur optimale. Dans le cas d'un problème en variables continues, l'appel est différent : z = glp_get_obj_val(prob); */ for(i = 0;i < NBVAR; i++) x[i] = glp_mip_col_val(prob,i+1); /* Récupération de la valeur des variables, Appel différent dans le cas d'un problème en variables continues : for(i = 0;i < p.nbvar;i++) x[i] = glp_get_col_prim(prob,i+1); */ printf("z = %lf\n",z); for(i = 0;i < NBVAR;i++) printf("x%c = %d, ",'B'+i,(int)(x[i] + 0.5)); /* un cast est ajouté, x[i] pourrait être égal à 0.99999... */ puts(""); /* Libération de la mémoire */ glp_delete_prob(prob); free(p); return 0; }
/** * Solves the LP problem * * @param mlp the MLP Handle * @param s_ctx context to return results * @return GNUNET_OK if could be solved, GNUNET_SYSERR on failure */ static int mlp_solve_lp_problem (struct GAS_MLP_Handle *mlp, struct GAS_MLP_SolutionContext *s_ctx) { int res; struct GNUNET_TIME_Relative duration; struct GNUNET_TIME_Absolute end; struct GNUNET_TIME_Absolute start = GNUNET_TIME_absolute_get(); /* LP presolver? * Presolver is required if the problem was modified and an existing * valid basis is now invalid */ if (mlp->presolver_required == GNUNET_YES) mlp->control_param_lp.presolve = GLP_ON; else mlp->control_param_lp.presolve = GLP_OFF; /* Solve LP problem to have initial valid solution */ lp_solv: res = glp_simplex(mlp->prob, &mlp->control_param_lp); if (res == 0) { /* The LP problem instance has been successfully solved. */ } else if (res == GLP_EITLIM) { /* simplex iteration limit has been exceeded. */ // TODO Increase iteration limit? } else if (res == GLP_ETMLIM) { /* Time limit has been exceeded. */ // TODO Increase time limit? } else { /* Problem was ill-defined, retry with presolver */ if (mlp->presolver_required == GNUNET_NO) { mlp->presolver_required = GNUNET_YES; goto lp_solv; } else { /* Problem was ill-defined, no way to handle that */ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "ats-mlp", "Solving LP problem failed: %i %s\n", res, mlp_solve_to_string(res)); return GNUNET_SYSERR; } } end = GNUNET_TIME_absolute_get (); duration = GNUNET_TIME_absolute_get_difference (start, end); mlp->lp_solved++; mlp->lp_total_duration =+ duration.rel_value; s_ctx->lp_duration = duration; GNUNET_STATISTICS_update (mlp->stats,"# LP problem solved", 1, GNUNET_NO); GNUNET_STATISTICS_set (mlp->stats,"# LP execution time (ms)", duration.rel_value, GNUNET_NO); GNUNET_STATISTICS_set (mlp->stats,"# LP execution time average (ms)", mlp->lp_total_duration / mlp->lp_solved, GNUNET_NO); /* Analyze problem status */ res = glp_get_status (mlp->prob); switch (res) { /* solution is optimal */ case GLP_OPT: /* solution is feasible */ case GLP_FEAS: break; /* Problem was ill-defined, no way to handle that */ default: GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "ats-mlp", "Solving LP problem failed, no solution: %s\n", mlp_status_to_string(res)); return GNUNET_SYSERR; break; } /* solved sucessfully, no presolver required next time */ mlp->presolver_required = GNUNET_NO; return GNUNET_OK; }
int main(int argc, char *argv[]) { /* structures de données propres à GLPK */ glp_prob *prob; // déclaration d'un pointeur sur le problème int ia[1 + NBCREUX]; int ja[1 + NBCREUX]; double ar[1 + NBCREUX]; // déclaration des 3 tableaux servant à définir la partie creuse de la matrice des contraintes int p[N+1]; p[1] = 34; p[2] = 6; p[3] = 8; p[4] = 17; p[5] = 16; p[6] = 5; p[7] = 13; p[8] = 21; p[9] = 25; p[10] = 31; p[11] = 14; p[12] = 13; p[13] = 33; p[14] = 9; p[15] = 25; p[16] = 25; /* variables récupérant les résultats de la résolution du problème (fonction objectif et valeur des variables) */ int i,j,pos; double z; double x[NBVAR]; /* Les déclarations suivantes sont optionnelles, leur but est de donner des noms aux variables et aux contraintes. Cela permet de lire plus facilement le modèle saisi si on en demande un affichage à GLPK, ce qui est souvent utile pour détecter une erreur! */ char nomcontr[NBCONTR][8]; /* ici, les contraintes seront nommées "caisse1", "caisse2",... */ char numero[NBCONTR][3]; /* pour un nombre à deux chiffres */ char nomvar[NBVAR][3]; /* "xA", "xB", ... */ /* Création d'un problème (initialement vide) */ prob = glp_create_prob(); /* allocation mémoire pour le problème */ glp_set_prob_name(prob, "wagons"); /* affectation d'un nom (on pourrait mettre NULL) */ glp_set_obj_dir(prob, GLP_MIN); /* Il s'agit d'un problème de minimisation, on utiliserait la constante GLP_MAX dans le cas contraire */ /* Déclaration du nombre de contraintes (nombre de lignes de la matrice des contraintes) : NBCONTR */ glp_add_rows(prob, NBCONTR); /* On commence par préciser les bornes sur les constrainte, les indices des contraintes commencent à 1 (!) dans GLPK */ for(i = 1;i <= N;i++) { /* partie optionnelle : donner un nom aux contraintes */ strcpy(nomcontr[i-1], "caisse"); sprintf(numero[i-1], "%d", i); strcat(nomcontr[i-1], numero[i-1]); /* Les contraintes sont nommés "salle1", "salle2"... */ glp_set_row_name(prob, i, nomcontr[i-1]); /* Affectation du nom à la contrainte i */ /* partie indispensable : les bornes sur les contraintes */ glp_set_row_bnds(prob, i, GLP_FX, 1.0, 1.0); } for(i = N+1;i <= NBCONTR;i++) { /* partie optionnelle : donner un nom aux contraintes */ strcpy(nomcontr[i-1], "chaMax"); sprintf(numero[i-1], "%d", i); strcat(nomcontr[i-1], numero[i-1]); /* Les contraintes sont nommés "chargemax", "chargemax2"... */ glp_set_row_name(prob, i, nomcontr[i-1]); /* Affectation du nom à la contrainte i */ // il doit manquer un bout ici glp_set_row_bnds(prob, i, GLP_UP, 0.0, 0.0); //<=0 // on met cmax a gauche car c'est une variable // il aura le coeff -1 dans la mat creuse } /* Déclaration du nombre de variables : NBVAR */ glp_add_cols(prob, NBVAR); /* On précise le type des variables, les indices commencent à 1 également pour les variables! */ for(i = 1;i <= NBVAR;i++) { if(i==NBVAR){ sprintf(nomvar[i-1],"Cm"); glp_set_col_name(prob, i , nomvar[i-1]); glp_set_col_bnds(prob, i, GLP_LO, 0.0, 0.0); }else{ /* partie optionnelle : donner un nom aux variables */ sprintf(nomvar[i-1],"x%d",i-1); glp_set_col_name(prob, i , nomvar[i-1]); /* Les variables sont nommées "xA", "xB"... afin de respecter les noms de variables de l'exercice 2.2 */ /* partie obligatoire : bornes éventuelles sur les variables, et type */ glp_set_col_bnds(prob, i, GLP_DB, 0.0, 1.0); /* bornes sur les variables, comme sur les contraintes */ glp_set_col_kind(prob, i, GLP_BV); /* les variables sont par défaut continues, nous précisons ici qu'elles sont binaires avec la constante GLP_BV, on utiliserait GLP_IV pour des variables entières */ } } /* définition des coefficients des variables dans la fonction objectif */ for(i = 1;i <= N*M;i++) glp_set_obj_coef(prob,i,0.0); // Tous les coûts sont ici à 0! Mais on doit specifier quand meme glp_set_obj_coef(prob,N*M+1,1.0); // 1 fois cmax /* Définition des coefficients non-nuls dans la matrice des contraintes, autrement dit les coefficients de la matrice creuse */ /* Les indices commencent également à 1 ! */ // pour i de 1 a n //pour i de 1 a m /* xij intervient dans la ligne i avec un coeff 1 et dans la ligne n+j avec un coeff pi ia -> i et n+j ar -> 1 et pi ja -> xij -> (i-1)*m+j */ pos = 1; for(i=1; i<=N; i++){ for(j=1; j<=M; j++){ ia[pos] = i; ja[pos] = (i-1)*M+j; ar[pos] = 1; pos++; ia[pos] = N+j; ja[pos] = (i-1)*M+j; ar[pos] = p[i]; pos++; } } //Cmax a -1 !!! for(i=N+1; i<=N+M;i++){ ia[pos] = i; ja[pos] = N*M+1; ar[pos] = -1; pos++; } /* chargement de la matrice dans le problème */ glp_load_matrix(prob,NBCREUX,ia,ja,ar); /* Optionnel : écriture de la modélisation dans un fichier (TRES utile pour debugger!) */ glp_write_lp(prob,NULL,"wagons.lp"); /* Résolution, puis lecture des résultats */ glp_simplex(prob,NULL); glp_intopt(prob,NULL); /* Résolution */ z = glp_mip_obj_val(prob); /* Récupération de la valeur optimale. Dans le cas d'un problème en variables continues, l'appel est différent : z = glp_get_obj_val(prob); */ for(i = 0;i < NBVAR; i++) x[i] = glp_mip_col_val(prob,i+1); /* Récupération de la valeur des variables, Appel différent dans le cas d'un problème en variables continues : for(i = 0;i < p.nbvar;i++) x[i] = glp_get_col_prim(prob,i+1); */ printf("z = %lf\n",z); for(i = 0;i < NBVAR;i++) printf("x%d = %d, ",i,(int)(x[i] + 0.5)); /* un cast est ajouté, x[i] pourrait être égal à 0.99999... */ puts(""); /* libération mémoire */ glp_delete_prob(prob); /* J'adore qu'un plan se déroule sans accroc! */ return 0; }
static void maybe_check_results(const int ppl_status, const double ppl_optimum_value) { const char* ppl_status_string; const char* glpk_status_string; int glpk_status; int treat_as_lp = 0; glp_smcp glpk_smcp; if (!check_results) return; if (no_mip || glpk_lp_num_int == 0) treat_as_lp = 1; glp_set_obj_dir(glpk_lp, (maximize ? GLP_MAX : GLP_MIN)); glp_init_smcp(&glpk_smcp); /* Disable GLPK output. */ glpk_smcp.msg_lev = GLP_MSG_OFF; if (treat_as_lp) { /* Set the problem class to LP: MIP problems are thus treated as LP ones. */ glp_exact(glpk_lp, &glpk_smcp); glpk_status = glp_get_status(glpk_lp); } else { /* MIP case. */ glp_simplex(glpk_lp, &glpk_smcp); glpk_status = glp_get_status(glpk_lp); if (glpk_status != GLP_NOFEAS && glpk_status != GLP_UNBND) { glp_iocp glpk_iocp; glp_init_iocp(&glpk_iocp); /* Disable GLPK output. */ glpk_iocp.msg_lev = GLP_MSG_OFF; glp_intopt(glpk_lp, &glpk_iocp); glpk_status = glp_mip_status(glpk_lp); } } /* If no_optimization is enabled, the second case is not possibile. */ if (!((ppl_status == PPL_MIP_PROBLEM_STATUS_UNFEASIBLE && glpk_status == GLP_NOFEAS) || (ppl_status == PPL_MIP_PROBLEM_STATUS_UNBOUNDED && glpk_status == GLP_UNBND) || (ppl_status == PPL_MIP_PROBLEM_STATUS_OPTIMIZED && (glpk_status == GLP_OPT /* If no_optimization is enabled, check if the problem is unbounded for GLPK. */ || (no_optimization && (glpk_status == GLP_UNBND || glpk_status == GLP_UNDEF)))))) { if (ppl_status == PPL_MIP_PROBLEM_STATUS_UNFEASIBLE) ppl_status_string = "unfeasible"; else if (ppl_status == PPL_MIP_PROBLEM_STATUS_UNBOUNDED) ppl_status_string = "unbounded"; else if (ppl_status == PPL_MIP_PROBLEM_STATUS_OPTIMIZED) ppl_status_string = "optimizable"; else ppl_status_string = "<?>"; switch (glpk_status) { case GLP_NOFEAS: glpk_status_string = "unfeasible"; break; case GLP_UNBND: glpk_status_string = "unbounded"; break; case GLP_OPT: glpk_status_string = "optimizable"; break; case GLP_UNDEF: glpk_status_string = "undefined"; break; default: glpk_status_string = "<?>"; break; } error("check failed: for GLPK the problem is %s, not %s", glpk_status_string, ppl_status_string); check_results_failed = 1; } else if (!no_optimization && ppl_status == PPL_MIP_PROBLEM_STATUS_OPTIMIZED) { double glpk_optimum_value = (treat_as_lp ? glp_get_obj_val(glpk_lp) : glp_mip_obj_val(glpk_lp)); if (fabs(ppl_optimum_value - glpk_optimum_value) > check_threshold) { error("check failed: for GLPK the problem's optimum is %.20g," " not %.20g", glpk_optimum_value, ppl_optimum_value); check_results_failed = 1; } } return; }
/* R is the random contraint data in row major memory layout ridx is an N array of integers soln is an array of length (n+1) soln[n] is t (objective value) active_constr is an N-length 0-1 array */ void solve_lp(int N, int n, double* R, int* ridx, double* soln, int* active_constr) { double tol = 1.0e-14; int size = (N+1)*(n+1) + 1; // We add one because GLPK indexes arrays // starting at 1 instead of 0. glp_prob *lp; int* ia = malloc(size * sizeof(int)); int* ja = malloc(size * sizeof(int)); double* ar = malloc(size * sizeof(double)); int i, j; lp = glp_create_prob(); glp_set_prob_name(lp, "portfolio"); glp_set_obj_dir(lp, GLP_MAX); glp_add_rows(lp, N+1); // Sampled constraints are ">= 0" for (i = 1; i <= N; i++) { glp_set_row_bnds(lp, i, GLP_LO, 0.0, 0.0); } // Sum = 1 constraint glp_set_row_name(lp, N+1, "sum"); glp_set_row_bnds(lp, N+1, GLP_FX, 1.0, 1.0); glp_add_cols(lp, n+1); // Nonnegative variables y for (i = 1; i <= n; i++) { glp_set_col_bnds(lp, i, GLP_LO, 0.0, 0.0); glp_set_obj_coef(lp, i, 0.0); } // Free variable t glp_set_col_name(lp, n+1, "t"); glp_set_col_bnds(lp, n+1, GLP_FR, 0.0, 0.0); glp_set_obj_coef(lp, n+1, 1.0); // for (i = 0; i < N*(n-1); i++) { // printf("%d: %g\n", i, R[i]); // } int idx = 1; // Sampled constraints for (i = 1; i <= N; i++) { // Uncertain assets for (j = 1; j < n; j++) { ia[idx] = i; ja[idx] = j; ar[idx] = R[ ridx[(i-1)] * (n-1) + (j-1) ]; idx += 1; } // Fixed return asset ia[idx] = i; ja[idx] = n; ar[idx] = 1.05; idx += 1; // t ia[idx] = i; ja[idx] = n+1; ar[idx] = -1.0; idx += 1; } // Sum = 1 constraint for (i = 1; i <= n; i++) { ia[idx] = N+1; ja[idx] = i; ar[idx] = 1.0; idx += 1; } // t ia[idx] = N+1; ja[idx] = n+1; ar[idx] = 0.0; idx += 1; // for (i = 1; i < size; i++) { // printf("%d %d %g\n", ia[i], ja[i], ar[i]); // } glp_load_matrix(lp, size-1, ia, ja, ar); // glp_scale_prob(lp, GLP_SF_AUTO); glp_smcp param; glp_init_smcp(¶m); param.meth = GLP_PRIMAL; //glp_std_basis(lp); glp_simplex(lp, ¶m); double z = glp_get_obj_val(lp); // printf("z = %g\n", z); if (soln) { for (i = 0; i < n; i++) { double y = glp_get_col_prim(lp, i+1); soln[i] = y; // printf("y%d = %g\n", i, y); } double t = glp_get_col_prim(lp, n+1); soln[n] = t; // printf("t = %g\n", glp_get_col_prim(lp, n+1)); } for (i = 1; i <= N; i++) { double slack = glp_get_row_prim(lp, i); active_constr[i-1] = fabs(slack) < tol ? 1 : 0; // printf("constr%d %d\n", i, active_constr[i-1]); } glp_delete_prob(lp); // glp_free_env(); free(ia); free(ja); free(ar); }
int CConstraints::GLPK_lp(CModel* pmodel) { glp_prob* lp = glp_create_prob(); int iRow = (int) m_vWeights.size(); //int iCol = (int) m_iWeightLength + m_iPatternNum; int iSize = iRow * ( m_iWeightLength + 1); int ia[10 + iSize], ja[1 + iSize]; double ar[1 + iSize]; glp_set_prob_name(lp, "StrLP"); glp_set_obj_dir(lp, GLP_MIN); glp_add_rows(lp, (int) m_vWeights.size()); // setup rows for (int i = 0; i < (int) m_vWeights.size(); i ++) { char tmp[200]; sprintf(tmp, "cc_%d", i + 1); glp_set_row_name(lp, i + 1, tmp); glp_set_row_bnds(lp, i + 1, GLP_LO, m_fDistance - m_fEpsilon, 0); } glp_add_cols(lp, m_iWeightLength + m_iPatternNum); for (int i = 0; i < m_iWeightLength; i ++) { char tmp[200]; sprintf(tmp, "w%d", i + 1); glp_set_col_name(lp, i + 1, tmp); glp_set_col_bnds(lp, i + 1, GLP_LO, 0, 0.0); glp_set_obj_coef(lp, i + 1, 1.0); } for (int i = 0; i < m_iPatternNum; i ++) { char tmp[200]; sprintf(tmp, "e%d", i + 1); glp_set_col_name(lp, m_iWeightLength + i + 1, tmp); glp_set_col_bnds(lp, m_iWeightLength + i + 1, GLP_LO, 0, 0.0); glp_set_obj_coef(lp, m_iWeightLength + i + 1, m_fC / m_iPatternNum); } int iIndex = 1; for (int i = 0; i < (int)m_vWeights.size(); i ++) { double* pd = m_vWeights[i]; for (int j = 0; j < (int) m_iWeightLength; j ++) { ia[iIndex] = i + 1, ja[iIndex] = j + 1; if (pmodel->m_vSign[j] <= 0) { ar[iIndex] = -pd[j]; } else { ar[iIndex] = pd[j]; } iIndex ++; } ia[iIndex] = i + 1; ja[iIndex] = m_iWeightLength + m_vPatternIndex[i] + 1; //ar[iIndex] = 1; ar[iIndex] = m_vLoss[i]; iIndex ++; } glp_load_matrix(lp, iIndex - 1, ia, ja, ar); glp_simplex(lp, NULL); double z = glp_get_obj_val(lp); fprintf(stderr, "minimal value %f \n", z); for (int i = 0; i < m_iWeightLength; i ++) { double x = glp_get_col_prim(lp, i + 1); if (pmodel->m_vSign[i] <=0) { pmodel->m_vWeight[i] = -x; } else { pmodel->m_vWeight[i] = x; } if (x != 0) fprintf(stderr, "(w%d, %f)\t", i + 1, pmodel->m_vWeight[i]); } for (int i = 0; i < m_iPatternNum; i ++) { double x = glp_get_col_prim(lp, m_iWeightLength + i + 1); pmodel->m_vTheta[i] = x; if (x != 0) fprintf(stderr, "(e%d, %f)\t", i + 1, pmodel->m_vTheta[i]); } glp_delete_prob(lp); return 1; }
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; #if 0 /* 11/VII-2013 */ ret = solve_mip(mip, parm); #else if (parm->use_sol) { mip->mip_stat = P->mip_stat; mip->mip_obj = P->mip_obj; } ret = solve_mip(mip, parm, P, npp); #endif 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; }
OptSolutionData* GLPKRunSolver(int ProbType) { OptSolutionData* NewSolution = NULL; int NumVariables = glp_get_num_cols(GLPKModel); int Status = 0; if (ProbType == MILP) { Status = glp_simplex(GLPKModel, NULL); // Use default settings if (Status != 0) { FErrorFile() << "Failed to optimize problem." << endl; FlushErrorFile(); return NULL; } Status = glp_intopt(GLPKModel, NULL); // Use default settings if (Status != 0) { FErrorFile() << "Failed to optimize problem." << endl; FlushErrorFile(); return NULL; } NewSolution = new OptSolutionData; Status = glp_mip_status(GLPKModel); if (Status == GLP_UNDEF || Status == GLP_NOFEAS) { NewSolution->Status = INFEASIBLE; return NewSolution; } else if (Status == GLP_FEAS) { NewSolution->Status = UNBOUNDED; return NewSolution; } else if (Status == GLP_OPT) { NewSolution->Status = SUCCESS; } else { delete NewSolution; FErrorFile() << "Problem status unrecognized." << endl; FlushErrorFile(); return NULL; } NewSolution->Objective = glp_mip_obj_val(GLPKModel); NewSolution->SolutionData.resize(NumVariables); for (int i=0; i < NumVariables; i++) { NewSolution->SolutionData[i] = glp_mip_col_val(GLPKModel, i+1); } } else if (ProbType == LP) { //First we check the basis matrix to ensure it is not singular if (glp_warm_up(GLPKModel) != 0) { glp_adv_basis(GLPKModel, 0); } Status = glp_simplex(GLPKModel, NULL); // Use default settings if (Status == GLP_EBADB) { /* the basis is invalid; build some valid basis */ glp_adv_basis(GLPKModel, 0); Status = glp_simplex(GLPKModel, NULL); // Use default settings } if (Status != 0) { FErrorFile() << "Failed to optimize problem." << endl; FlushErrorFile(); return NULL; } NewSolution = new OptSolutionData; Status = glp_get_status(GLPKModel); if (Status == GLP_INFEAS || Status == GLP_NOFEAS || Status == GLP_UNDEF) { cout << "Model is infeasible" << endl; FErrorFile() << "Model is infeasible" << endl; FlushErrorFile(); NewSolution->Status = INFEASIBLE; return NewSolution; } else if (Status == GLP_FEAS || Status == GLP_UNBND) { cout << "Model is unbounded" << endl; FErrorFile() << "Model is unbounded" << endl; FlushErrorFile(); NewSolution->Status = UNBOUNDED; return NewSolution; } else if (Status == GLP_OPT) { NewSolution->Status = SUCCESS; } else { delete NewSolution; FErrorFile() << "Problem status unrecognized." << endl; FlushErrorFile(); return NULL; } NewSolution->Objective = glp_get_obj_val(GLPKModel); NewSolution->SolutionData.resize(NumVariables); for (int i=0; i < NumVariables; i++) { NewSolution->SolutionData[i] = glp_get_col_prim(GLPKModel, i+1); } } else { FErrorFile() << "Optimization problem type cannot be handled by GLPK solver." << endl; FlushErrorFile(); return NULL; } return NewSolution; }
int glpk (int sense, int n, int m, double *c, int nz, int *rn, int *cn, double *a, double *b, char *ctype, int *freeLB, double *lb, int *freeUB, double *ub, int *vartype, int isMIP, int lpsolver, int save_pb, char *save_filename, char *filetype, double *xmin, double *fmin, double *status, double *lambda, double *redcosts, double *time, double *mem) { int typx = 0; int method; clock_t t_start = clock(); //Redirect standard output if (glpIntParam[0] > 1) glp_term_hook (glpk_print_hook, NULL); else glp_term_hook (NULL, NULL); //-- Create an empty LP/MILP object LPX *lp = lpx_create_prob (); //-- Set the sense of optimization if (sense == 1) glp_set_obj_dir (lp, GLP_MIN); else glp_set_obj_dir (lp, GLP_MAX); //-- Define the number of unknowns and their domains. glp_add_cols (lp, n); for (int i = 0; i < n; i++) { //-- Define type of the structural variables if (! freeLB[i] && ! freeUB[i]) { if ( lb[i] == ub[i] ) glp_set_col_bnds (lp, i+1, GLP_FX, lb[i], ub[i]); else glp_set_col_bnds (lp, i+1, GLP_DB, lb[i], ub[i]); } else { if (! freeLB[i] && freeUB[i]) glp_set_col_bnds (lp, i+1, GLP_LO, lb[i], ub[i]); else { if (freeLB[i] && ! freeUB[i]) glp_set_col_bnds (lp, i+1, GLP_UP, lb[i], ub[i]); else glp_set_col_bnds (lp, i+1, GLP_FR, lb[i], ub[i]); } } // -- Set the objective coefficient of the corresponding // -- structural variable. No constant term is assumed. glp_set_obj_coef(lp,i+1,c[i]); if (isMIP) glp_set_col_kind (lp, i+1, vartype[i]); } glp_add_rows (lp, m); for (int i = 0; i < m; i++) { /* If the i-th row has no lower bound (types F,U), the corrispondent parameter will be ignored. If the i-th row has no upper bound (types F,L), the corrispondent parameter will be ignored. If the i-th row is of S type, the i-th LB is used, but the i-th UB is ignored. */ switch (ctype[i]) { case 'F': typx = GLP_FR; break; // upper bound case 'U': typx = GLP_UP; break; // lower bound case 'L': typx = GLP_LO; break; // fixed constraint case 'S': typx = GLP_FX; break; // double-bounded variable case 'D': typx = GLP_DB; break; } if ( typx == GLP_DB && -b[i] < b[i]) { glp_set_row_bnds (lp, i+1, typx, -b[i], b[i]); } else if(typx == GLP_DB && -b[i] == b[i]) { glp_set_row_bnds (lp, i+1, GLP_FX, b[i], b[i]); } else { // this should be glp_set_row_bnds (lp, i+1, typx, -b[i], b[i]); glp_set_row_bnds (lp, i+1, typx, b[i], b[i]); } } // Load constraint matrix A glp_load_matrix (lp, nz, rn, cn, a); // Save problem if (save_pb) { if (!strcmp(filetype,"cplex")){ if (glp_write_lp (lp, NULL, save_filename) != 0) { mexErrMsgTxt("glpk: unable to write the problem"); longjmp (mark, -1); } }else{ if (!strcmp(filetype,"fixedmps")){ if (glp_write_mps (lp, GLP_MPS_DECK, NULL, save_filename) != 0) { mexErrMsgTxt("glpk: unable to write the problem"); longjmp (mark, -1); } }else{ if (!strcmp(filetype,"freemps")){ if (glp_write_mps (lp, GLP_MPS_FILE, NULL, save_filename) != 0) { mexErrMsgTxt("glpk: unable to write the problem"); longjmp (mark, -1); } }else{// plain text if (lpx_print_prob (lp, save_filename) != 0) { mexErrMsgTxt("glpk: unable to write the problem"); longjmp (mark, -1); } } } } } //-- scale the problem data (if required) if (! glpIntParam[16] || lpsolver != 1) { switch ( glpIntParam[1] ) { case ( 0 ): glp_scale_prob( lp, GLP_SF_SKIP ); break; case ( 1 ): glp_scale_prob( lp, GLP_SF_GM ); break; case ( 2 ): glp_scale_prob( lp, GLP_SF_EQ ); break; case ( 3 ): glp_scale_prob( lp, GLP_SF_AUTO ); break; case ( 4 ): glp_scale_prob( lp, GLP_SF_2N ); break; default : mexErrMsgTxt("glpk: unrecognized scaling option"); longjmp (mark, -1); } } else { /* do nothing? or unscale? glp_unscale_prob( lp ); */ } //-- build advanced initial basis (if required) if (lpsolver == 1 && ! glpIntParam[16]) glp_adv_basis (lp, 0); glp_smcp sParam; glp_init_smcp(&sParam); //-- set control parameters for simplex/exact method if (lpsolver == 1 || lpsolver == 3){ //remap of control parameters for simplex method sParam.msg_lev=glpIntParam[0]; // message level // simplex method: primal/dual switch ( glpIntParam[2] ) { case 0: sParam.meth=GLP_PRIMAL; break; case 1: sParam.meth=GLP_DUAL; break; case 2: sParam.meth=GLP_DUALP; break; default: mexErrMsgTxt("glpk: unrecognized primal/dual method"); longjmp (mark, -1); } // pricing technique if (glpIntParam[3]==0) sParam.pricing=GLP_PT_STD; else sParam.pricing=GLP_PT_PSE; // ratio test if (glpIntParam[20]==0) sParam.r_test = GLP_RT_STD; else sParam.r_test=GLP_RT_HAR; //tollerances sParam.tol_bnd=glpRealParam[1]; // primal feasible tollerance sParam.tol_dj=glpRealParam[2]; // dual feasible tollerance sParam.tol_piv=glpRealParam[3]; // pivot tollerance sParam.obj_ll=glpRealParam[4]; // lower limit sParam.obj_ul=glpRealParam[5]; // upper limit // iteration limit if (glpIntParam[5]==-1) sParam.it_lim=INT_MAX; else sParam.it_lim=glpIntParam[5]; // time limit if (glpRealParam[6]==-1) sParam.tm_lim=INT_MAX; else sParam.tm_lim=(int) glpRealParam[6]; sParam.out_frq=glpIntParam[7]; // output frequency sParam.out_dly=(int) glpRealParam[7]; // output delay // presolver if (glpIntParam[16]) sParam.presolve=GLP_ON; else sParam.presolve=GLP_OFF; }else{ for(int i = 0; i < NIntP; i++) { // skip assinging ratio test or if ( i == 18 || i == 20) continue; lpx_set_int_parm (lp, IParam[i], glpIntParam[i]); } for (int i = 0; i < NRealP; i++) { lpx_set_real_parm (lp, RParam[i], glpRealParam[i]); } } //set MIP params if MIP.... glp_iocp iParam; glp_init_iocp(&iParam); if ( isMIP ){ method = 'I'; switch (glpIntParam[0]) { //message level case 0: iParam.msg_lev = GLP_MSG_OFF; break; case 1: iParam.msg_lev = GLP_MSG_ERR; break; case 2: iParam.msg_lev = GLP_MSG_ON; break; case 3: iParam.msg_lev = GLP_MSG_ALL; break; default: mexErrMsgTxt("glpk: msg_lev bad param"); } switch (glpIntParam[14]) { //branching param case 0: iParam.br_tech = GLP_BR_FFV; break; case 1: iParam.br_tech = GLP_BR_LFV; break; case 2: iParam.br_tech = GLP_BR_MFV; break; case 3: iParam.br_tech = GLP_BR_DTH; break; default: mexErrMsgTxt("glpk: branch bad param"); } switch (glpIntParam[15]) { //backtracking heuristic case 0: iParam.bt_tech = GLP_BT_DFS; break; case 1: iParam.bt_tech = GLP_BT_BFS; break; case 2: iParam.bt_tech = GLP_BT_BLB; break; case 3: iParam.bt_tech = GLP_BT_BPH; break; default: mexErrMsgTxt("glpk: backtrack bad param"); } if ( glpRealParam[8] > 0.0 && glpRealParam[8] < 1.0 ) iParam.tol_int = glpRealParam[8]; // absolute tolorence else mexErrMsgTxt("glpk: tolint must be between 0 and 1"); iParam.tol_obj = glpRealParam[9]; // relative tolarence iParam.mip_gap = glpRealParam[10]; // realative gap tolerance // set time limit for mip if ( glpRealParam[6] < 0.0 || glpRealParam[6] > 1e6 ) iParam.tm_lim = INT_MAX; else iParam.tm_lim = (int)(1000.0 * glpRealParam[6] ); // Choose Cutsets for mip // shut all cuts off, then start over.... iParam.gmi_cuts = GLP_OFF; iParam.mir_cuts = GLP_OFF; iParam.cov_cuts = GLP_OFF; iParam.clq_cuts = GLP_OFF; switch( glpIntParam[17] ) { case 0: break; case 1: iParam.gmi_cuts = GLP_ON; break; case 2: iParam.mir_cuts = GLP_ON; break; case 3: iParam.cov_cuts = GLP_ON; break; case 4: iParam.clq_cuts = GLP_ON; break; case 5: iParam.clq_cuts = GLP_ON; iParam.gmi_cuts = GLP_ON; iParam.mir_cuts = GLP_ON; iParam.cov_cuts = GLP_ON; iParam.clq_cuts = GLP_ON; break; default: mexErrMsgTxt("glpk: cutset bad param"); } switch( glpIntParam[18] ) { // pre-processing for mip case 0: iParam.pp_tech = GLP_PP_NONE; break; case 1: iParam.pp_tech = GLP_PP_ROOT; break; case 2: iParam.pp_tech = GLP_PP_ALL; break; default: mexErrMsgTxt("glpk: pprocess bad param"); } if (glpIntParam[16]) iParam.presolve=GLP_ON; else iParam.presolve=GLP_OFF; if (glpIntParam[19]) iParam.binarize = GLP_ON; else iParam.binarize = GLP_OFF; } else { /* Choose simplex method ('S') or interior point method ('T') or Exact method ('E') to solve the problem */ switch (lpsolver) { case 1: method = 'S'; break; case 2: method = 'T'; break; case 3: method = 'E'; break; default: mexErrMsgTxt("glpk: lpsolver != lpsolver"); longjmp (mark, -1); } } // now run the problem... int errnum = 0; switch (method) { case 'I': errnum = glp_intopt( lp, &iParam ); errnum += 200; //this is to avoid ambiguity in the return codes. break; case 'S': errnum = glp_simplex(lp, &sParam); errnum += 100; //this is to avoid ambiguity in the return codes. break; case 'T': errnum = glp_interior(lp, NULL ); errnum += 300; //this is to avoid ambiguity in the return codes. break; case 'E': errnum = glp_exact(lp, &sParam); errnum += 100; //this is to avoid ambiguity in the return codes. break; default: /*xassert (method != method); */ mexErrMsgTxt("glpk: method != method"); longjmp (mark, -1); } if (errnum==100 || errnum==200 || errnum==300 || errnum==106 || errnum==107 || errnum==108 || errnum==109 || errnum==209 || errnum==214 || errnum==308) { // Get status and object value if (isMIP) { *status = glp_mip_status (lp); *fmin = glp_mip_obj_val (lp); } else { if (lpsolver == 1 || lpsolver == 3) { *status = glp_get_status (lp); *fmin = glp_get_obj_val (lp); } else { *status = glp_ipt_status (lp); *fmin = glp_ipt_obj_val (lp); } } // Get optimal solution (if exists) if (isMIP) { for (int i = 0; i < n; i++) xmin[i] = glp_mip_col_val (lp, i+1); } else { /* Primal values */ for (int i = 0; i < n; i++) { if (lpsolver == 1 || lpsolver == 3) xmin[i] = glp_get_col_prim (lp, i+1); else xmin[i] = glp_ipt_col_prim (lp, i+1); } /* Dual values */ for (int i = 0; i < m; i++) { if (lpsolver == 1 || lpsolver == 3) lambda[i] = glp_get_row_dual (lp, i+1); else lambda[i] = glp_ipt_row_dual (lp, i+1); } /* Reduced costs */ for (int i = 0; i < glp_get_num_cols (lp); i++) { if (lpsolver == 1 || lpsolver == 3) redcosts[i] = glp_get_col_dual (lp, i+1); else redcosts[i] = glp_ipt_col_dual (lp, i+1); } } *time = (clock () - t_start) / CLOCKS_PER_SEC; size_t tpeak; glp_mem_usage(NULL, NULL, NULL, &tpeak); *mem=((double) tpeak) / (1024); lpx_delete_prob(lp); return 0; } else { // printf("errnum is %d\n", errnum); } lpx_delete_prob(lp); /* this shouldn't be nessiary with glp_deleted_prob, but try it if we have weird behavior again... */ glp_free_env(); *status = errnum; return errnum; }
static double eval_degrad(glp_prob *P, int j, double bnd) { /* compute degradation of the objective on fixing x[j] at given value with a limited number of dual simplex iterations */ /* this routine fixes column x[j] at specified value bnd, solves resulting LP, and returns a lower bound to degradation of the objective, degrad >= 0 */ glp_prob *lp; glp_smcp parm; int ret; double degrad; /* the current basis must be optimal */ xassert(glp_get_status(P) == GLP_OPT); /* create a copy of P */ lp = glp_create_prob(); glp_copy_prob(lp, P, 0); /* fix column x[j] at specified value */ glp_set_col_bnds(lp, j, GLP_FX, bnd, bnd); /* try to solve resulting LP */ glp_init_smcp(&parm); parm.msg_lev = GLP_MSG_OFF; parm.meth = GLP_DUAL; parm.it_lim = 30; parm.out_dly = 1000; parm.meth = GLP_DUAL; ret = glp_simplex(lp, &parm); if (ret == 0 || ret == GLP_EITLIM) { if (glp_get_prim_stat(lp) == GLP_NOFEAS) { /* resulting LP has no primal feasible solution */ degrad = DBL_MAX; } else if (glp_get_dual_stat(lp) == GLP_FEAS) { /* resulting basis is optimal or at least dual feasible, so we have the correct lower bound to degradation */ if (P->dir == GLP_MIN) degrad = lp->obj_val - P->obj_val; else if (P->dir == GLP_MAX) degrad = P->obj_val - lp->obj_val; else xassert(P != P); /* degradation cannot be negative by definition */ /* note that the lower bound to degradation may be close to zero even if its exact value is zero due to round-off errors on computing the objective value */ if (degrad < 1e-6 * (1.0 + 0.001 * fabs(P->obj_val))) degrad = 0.0; } else { /* the final basis reported by the simplex solver is dual infeasible, so we cannot determine a non-trivial lower bound to degradation */ degrad = 0.0; } } else { /* the simplex solver failed */ degrad = 0.0; } /* delete the copy of P */ glp_delete_prob(lp); return degrad; }
int glpk (int sense, int n, int m, double *c, int nz, int *rn, int *cn, double *a, double *b, char *ctype, int *freeLB, double *lb, int *freeUB, double *ub, int *vartype, int isMIP, int lpsolver, int save_pb, char *save_filename, char *filetype, double *xmin, double *fmin, double *status, double *lambda, double *redcosts, double *time, double *mem) { int typx = 0; int method; clock_t t_start = clock(); // Obsolete //lib_set_fault_hook (NULL, glpk_fault_hook); //Redirect standard output if (glpIntParam[0] > 1) glp_term_hook (glpk_print_hook, NULL); else glp_term_hook (NULL, NULL); //-- Create an empty LP/MILP object glp_prob *lp = glp_create_prob (); //-- Set the sense of optimization if (sense == 1) glp_set_obj_dir (lp, GLP_MIN); else glp_set_obj_dir (lp, GLP_MAX); //-- Define the number of unknowns and their domains. glp_add_cols (lp, n); for (int i = 0; i < n; i++) { //-- Define type of the structural variables if (! freeLB[i] && ! freeUB[i]) glp_set_col_bnds (lp, i+1, GLP_DB, lb[i], ub[i]); else { if (! freeLB[i] && freeUB[i]) glp_set_col_bnds (lp, i+1, GLP_LO, lb[i], ub[i]); else { if (freeLB[i] && ! freeUB[i]) glp_set_col_bnds (lp, i+1, GLP_UP, lb[i], ub[i]); else glp_set_col_bnds (lp, i+1, GLP_FR, lb[i], ub[i]); } } // -- Set the objective coefficient of the corresponding // -- structural variable. No constant term is assumed. glp_set_obj_coef(lp,i+1,c[i]); if (isMIP) glp_set_col_kind (lp, i+1, vartype[i]); } glp_add_rows (lp, m); for (int i = 0; i < m; i++) { /* If the i-th row has no lower bound (types F,U), the corrispondent parameter will be ignored. If the i-th row has no upper bound (types F,L), the corrispondent parameter will be ignored. If the i-th row is of S type, the i-th LB is used, but the i-th UB is ignored. */ switch (ctype[i]) { case 'F': typx = GLP_FR; break; // upper bound case 'U': typx = GLP_UP; break; // lower bound case 'L': typx = GLP_LO; break; // fixed constraint case 'S': typx = GLP_FX; break; // double-bounded variable case 'D': typx = GLP_DB; break; } glp_set_row_bnds (lp, i+1, typx, b[i], b[i]); } // Load constraint matrix A glp_load_matrix (lp, nz, rn, cn, a); // Save problem if (save_pb) { if (!strcmp(filetype,"cplex")){ if (lpx_write_cpxlp (lp, save_filename) != 0) { mexErrMsgTxt("glpkcc: unable to write the problem"); longjmp (mark, -1); } }else{ if (!strcmp(filetype,"fixedmps")){ if (lpx_write_mps (lp, save_filename) != 0) { mexErrMsgTxt("glpkcc: unable to write the problem"); longjmp (mark, -1); } }else{ if (!strcmp(filetype,"freemps")){ if (lpx_write_freemps (lp, save_filename) != 0) { mexErrMsgTxt("glpkcc: unable to write the problem"); longjmp (mark, -1); } }else{// plain text if (lpx_print_prob (lp, save_filename) != 0) { mexErrMsgTxt("glpkcc: unable to write the problem"); longjmp (mark, -1); } } } } } //-- scale the problem data (if required) if (glpIntParam[1] && (! glpIntParam[16] || lpsolver != 1)) lpx_scale_prob (lp); //-- build advanced initial basis (if required) if (lpsolver == 1 && ! glpIntParam[16]) lpx_adv_basis (lp); glp_smcp sParam; glp_init_smcp(&sParam); //-- set control parameters if (lpsolver==1){ //remap of control parameters for simplex method sParam.msg_lev=glpIntParam[0]; // message level // simplex method: primal/dual if (glpIntParam[2]==0) sParam.meth=GLP_PRIMAL; else sParam.meth=GLP_DUALP; // pricing technique if (glpIntParam[3]==0) sParam.pricing=GLP_PT_STD; else sParam.pricing=GLP_PT_PSE; //sParam.r_test not available sParam.tol_bnd=glpRealParam[1]; // primal feasible tollerance sParam.tol_dj=glpRealParam[2]; // dual feasible tollerance sParam.tol_piv=glpRealParam[3]; // pivot tollerance sParam.obj_ll=glpRealParam[4]; // lower limit sParam.obj_ul=glpRealParam[5]; // upper limit // iteration limit if (glpIntParam[5]==-1) sParam.it_lim=INT_MAX; else sParam.it_lim=glpIntParam[5]; // time limit if (glpRealParam[6]==-1) sParam.tm_lim=INT_MAX; else sParam.tm_lim=(int) glpRealParam[6]; sParam.out_frq=glpIntParam[7]; // output frequency sParam.out_dly=(int) glpRealParam[7]; // output delay // presolver if (glpIntParam[16]) sParam.presolve=GLP_ON; else sParam.presolve=GLP_OFF; }else{ for(int i = 0; i < NIntP; i++) lpx_set_int_parm (lp, IParam[i], glpIntParam[i]); for (int i = 0; i < NRealP; i++) lpx_set_real_parm (lp, RParam[i], glpRealParam[i]); } // Choose simplex method ('S') or interior point method ('T') to solve the problem if (lpsolver == 1) method = 'S'; else method = 'T'; int errnum; switch (method){ case 'S': { if (isMIP){ method = 'I'; errnum = lpx_intopt (lp); } else{ errnum = glp_simplex(lp, &sParam); errnum += 100; //this is to avoid ambiguity in the return codes. } } break; case 'T': errnum = lpx_interior(lp); break; default: xassert (method != method); } /* errnum assumes the following results: errnum = 0 <=> No errors errnum = 1 <=> Iteration limit exceeded. errnum = 2 <=> Numerical problems with basis matrix. */ if (errnum == LPX_E_OK || errnum==100){ // Get status and object value if (isMIP) { *status = glp_mip_status (lp); *fmin = glp_mip_obj_val (lp); } else { if (lpsolver == 1) { *status = glp_get_status (lp); *fmin = glp_get_obj_val (lp); } else { *status = glp_ipt_status (lp); *fmin = glp_ipt_obj_val (lp); } } // Get optimal solution (if exists) if (isMIP) { for (int i = 0; i < n; i++) xmin[i] = glp_mip_col_val (lp, i+1); } else { /* Primal values */ for (int i = 0; i < n; i++) { if (lpsolver == 1) xmin[i] = glp_get_col_prim (lp, i+1); else xmin[i] = glp_ipt_col_prim (lp, i+1); } /* Dual values */ for (int i = 0; i < m; i++) { if (lpsolver == 1) lambda[i] = glp_get_row_dual (lp, i+1); else lambda[i] = glp_ipt_row_dual (lp, i+1); } /* Reduced costs */ for (int i = 0; i < glp_get_num_cols (lp); i++) { if (lpsolver == 1) redcosts[i] = glp_get_col_dual (lp, i+1); else redcosts[i] = glp_ipt_col_dual (lp, i+1); } } *time = (clock () - t_start) / CLOCKS_PER_SEC; glp_ulong tpeak; lib_mem_usage(NULL, NULL, NULL, &tpeak); *mem=(double)(4294967296.0 * tpeak.hi + tpeak.lo) / (1024); glp_delete_prob (lp); return 0; } glp_delete_prob (lp); *status = errnum; return errnum; }
static PyObject *simplex(PyObject *self, PyObject *args, PyObject *kwrds) { matrix *c, *h, *b=NULL, *x=NULL, *z=NULL, *y=NULL; PyObject *G, *A=NULL, *t=NULL; glp_prob *lp; glp_smcp *options = NULL; pysmcp *smcpParm = NULL; int m, n, p, i, j, k, nnz, nnzmax, *rn=NULL, *cn=NULL; double *a=NULL, val; char *kwlist[] = {"c", "G", "h", "A", "b","options", NULL}; if (!PyArg_ParseTupleAndKeywords(args, kwrds, "OOO|OOO!", kwlist, &c, &G, &h, &A, &b,&smcp_t,&smcpParm)) return NULL; if ((Matrix_Check(G) && MAT_ID(G) != DOUBLE) || (SpMatrix_Check(G) && SP_ID(G) != DOUBLE) || (!Matrix_Check(G) && !SpMatrix_Check(G))){ PyErr_SetString(PyExc_TypeError, "G must be a 'd' matrix"); return NULL; } if ((m = Matrix_Check(G) ? MAT_NROWS(G) : SP_NROWS(G)) <= 0) err_p_int("m"); if ((n = Matrix_Check(G) ? MAT_NCOLS(G) : SP_NCOLS(G)) <= 0) err_p_int("n"); if (!Matrix_Check(h) || h->id != DOUBLE) err_dbl_mtrx("h"); if (h->nrows != m || h->ncols != 1){ PyErr_SetString(PyExc_ValueError, "incompatible dimensions"); return NULL; } if (A){ if ((Matrix_Check(A) && MAT_ID(A) != DOUBLE) || (SpMatrix_Check(A) && SP_ID(A) != DOUBLE) || (!Matrix_Check(A) && !SpMatrix_Check(A))){ PyErr_SetString(PyExc_ValueError, "A must be a dense " "'d' matrix or a general sparse matrix"); return NULL; } if ((p = Matrix_Check(A) ? MAT_NROWS(A) : SP_NROWS(A)) < 0) err_p_int("p"); if ((Matrix_Check(A) ? MAT_NCOLS(A) : SP_NCOLS(A)) != n){ PyErr_SetString(PyExc_ValueError, "incompatible " "dimensions"); return NULL; } } else p = 0; if (b && (!Matrix_Check(b) || b->id != DOUBLE)) err_dbl_mtrx("b"); if ((b && (b->nrows != p || b->ncols != 1)) || (!b && p !=0 )){ PyErr_SetString(PyExc_ValueError, "incompatible dimensions"); return NULL; } if(!smcpParm) { smcpParm = (pysmcp*)malloc(sizeof(*smcpParm)); glp_init_smcp(&(smcpParm->obj)); } if(smcpParm) { Py_INCREF(smcpParm); options = &smcpParm->obj; options->presolve = 1; } lp = glp_create_prob(); glp_add_rows(lp, m+p); glp_add_cols(lp, n); for (i=0; i<n; i++){ glp_set_obj_coef(lp, i+1, MAT_BUFD(c)[i]); glp_set_col_bnds(lp, i+1, GLP_FR, 0.0, 0.0); } for (i=0; i<m; i++) glp_set_row_bnds(lp, i+1, GLP_UP, 0.0, MAT_BUFD(h)[i]); for (i=0; i<p; i++) glp_set_row_bnds(lp, i+m+1, GLP_FX, MAT_BUFD(b)[i], MAT_BUFD(b)[i]); nnzmax = (SpMatrix_Check(G) ? SP_NNZ(G) : m*n ) + ((A && SpMatrix_Check(A)) ? SP_NNZ(A) : p*n); a = (double *) calloc(nnzmax+1, sizeof(double)); rn = (int *) calloc(nnzmax+1, sizeof(int)); cn = (int *) calloc(nnzmax+1, sizeof(int)); if (!a || !rn || !cn){ free(a); free(rn); free(cn); glp_delete_prob(lp); return PyErr_NoMemory(); } nnz = 0; if (SpMatrix_Check(G)) { for (j=0; j<n; j++) for (k=SP_COL(G)[j]; k<SP_COL(G)[j+1]; k++) if ((val = SP_VALD(G)[k]) != 0.0){ a[1+nnz] = val; rn[1+nnz] = SP_ROW(G)[k]+1; cn[1+nnz] = j+1; nnz++; } } else for (j=0; j<n; j++) for (i=0; i<m; i++) if ((val = MAT_BUFD(G)[i+j*m]) != 0.0){ a[1+nnz] = val; rn[1+nnz] = i+1; cn[1+nnz] = j+1; nnz++; } if (A && SpMatrix_Check(A)){ for (j=0; j<n; j++) for (k=SP_COL(A)[j]; k<SP_COL(A)[j+1]; k++) if ((val = SP_VALD(A)[k]) != 0.0){ a[1+nnz] = val; rn[1+nnz] = m+SP_ROW(A)[k]+1; cn[1+nnz] = j+1; nnz++; } } else for (j=0; j<n; j++) for (i=0; i<p; i++) if ((val = MAT_BUFD(A)[i+j*p]) != 0.0){ a[1+nnz] = val; rn[1+nnz] = m+i+1; cn[1+nnz] = j+1; nnz++; } glp_load_matrix(lp, nnz, rn, cn, a); free(rn); free(cn); free(a); if (!(t = PyTuple_New(A ? 4 : 3))){ glp_delete_prob(lp); return PyErr_NoMemory(); } switch (glp_simplex(lp,options)){ case 0: x = (matrix *) Matrix_New(n,1,DOUBLE); z = (matrix *) Matrix_New(m,1,DOUBLE); if (A) y = (matrix *) Matrix_New(p,1,DOUBLE); if (!x || !z || (A && !y)){ Py_XDECREF(x); Py_XDECREF(z); Py_XDECREF(y); Py_XDECREF(t); Py_XDECREF(smcpParm); glp_delete_prob(lp); return PyErr_NoMemory(); } set_output_string(t,"optimal"); for (i=0; i<n; i++) MAT_BUFD(x)[i] = glp_get_col_prim(lp, i+1); PyTuple_SET_ITEM(t, 1, (PyObject *) x); for (i=0; i<m; i++) MAT_BUFD(z)[i] = -glp_get_row_dual(lp, i+1); PyTuple_SET_ITEM(t, 2, (PyObject *) z); if (A){ for (i=0; i<p; i++) MAT_BUFD(y)[i] = -glp_get_row_dual(lp, m+i+1); PyTuple_SET_ITEM(t, 3, (PyObject *) y); } Py_XDECREF(smcpParm); glp_delete_prob(lp); return (PyObject *) t; case GLP_EBADB: set_output_string(t,"incorrect initial basis"); break; case GLP_ESING: set_output_string(t,"singular initial basis matrix"); break; case GLP_ECOND: set_output_string(t,"ill-conditioned initial basis matrix"); break; case GLP_EBOUND: set_output_string(t,"incorrect bounds"); break; case GLP_EFAIL: set_output_string(t,"solver failure"); break; case GLP_EOBJLL: set_output_string(t,"objective function reached lower limit"); break; case GLP_EOBJUL: set_output_string(t,"objective function reached upper limit"); break; case GLP_EITLIM: set_output_string(t,"iteration limit exceeded"); break; case GLP_ETMLIM: set_output_string(t,"time limit exceeded"); break; case GLP_ENOPFS: set_output_string(t,"primal infeasible"); break; case GLP_ENODFS: set_output_string(t,"dual infeasible"); break; default: set_output_string(t,"unknown"); break; } Py_XDECREF(smcpParm); glp_delete_prob(lp); PyTuple_SET_ITEM(t, 1, Py_BuildValue("")); PyTuple_SET_ITEM(t, 2, Py_BuildValue("")); if (A) PyTuple_SET_ITEM(t, 3, Py_BuildValue("")); return (PyObject *) t; }
int CMyProblem::SolveLP() { return glp_simplex(lp, NULL); }
int main(int argc, char * argv[]) { int i,j; time(&initial); srand(SEED); /* Default values */ outFile = stdout; maxAlpha = 2; maxIter = 100; maxTime = 30; randomSeed = SEED; simpleOutput = 0; /* Read arguments */ if( argc > 7 ) argc = 7; switch(argc) { case 7: simpleOutput = atoi(argv[6]); case 6: if( !(randomSeed = atoi(argv[5])) ) leave(argv[0]); case 5: if( !(maxTime = atoi(argv[4])) ) leave(argv[0]); case 4: if( !(maxIter = atoi(argv[3])) ) leave(argv[0]); case 3: if( !(maxAlpha = atoi(argv[2])) ) leave(argv[0]); case 2: if( simpleOutput ) { if( !(outFile = fopen(argv[1],"a")) ) leave(argv[0]); break; } if( !(outFile = fopen(argv[1],"w")) ) leave(argv[0]); } readInput(stdin); /* Initiate positions */ for( i = 0 ; i < n ; ++i ) { pOrd[i].ideal = planes[i].ideal; pOrd[i].pos = i; } qsort (pOrd, n, sizeof(struct planeOrder), compIdealT); for( i = 0 ; i < n ; ++i ) { planes[pOrd[i].pos].pos = i; } /* Create lp instance */ glp_prob * Prob; Prob = glp_create_prob(); glp_set_prob_name(Prob, "Airplane Landing Problem"); glp_set_obj_name(Prob, "Cost"); /* Create basic constraints */ for( i = 0 ; i < n ; ++i ) { addBasicRestriction(Prob,i); } glp_create_index(Prob); /* Create separation constraints and order variables (&ij) if necessary */ for( i = 0 ; i < n ; ++i ) { for( j = i+1 ; j < n ; ++j ) { if( planes[i].latest >= planes[j].earliest && planes[j].latest >= planes[i].earliest ) { addOrderConstraint(Prob,i,j); } else if ( planes[i].latest < planes[j].earliest && planes[i].latest + planes[i].sep[j] >= planes[j].earliest ) { addSeparationConstraint(Prob, i, j); } else if ( planes[j].latest < planes[i].earliest && planes[j].latest + planes[j].sep[i] >= planes[i].earliest ) { addSeparationConstraint(Prob, j, i); } } } /* Write problem in MPS format so glpsol can (try to) solve it */ glp_write_mps(Prob, GLP_MPS_FILE, NULL,"mpsProblem.txt"); glp_delete_index(Prob); glp_create_index(Prob); /* GRASP */ /* Data to handle glp solving, time checking and solution generating */ glp_smcp * param = malloc(sizeof(glp_smcp)); glp_init_smcp(param); param->msg_lev = GLP_MSG_ERR; int solution[MAXSIZE], timeAux[MAXSIZE], t; double currResult = DBL_MAX, bestResult = DBL_MAX; alpha = 0; time_t start, curr; time(&start); for( t = 0 ; t < maxIter ; ++t ) { /* Greedy solution generation */ while(createSolution(solution,timeAux,0)) alpha = n; /* Building the right constraints */ mapSolution(Prob,solution); /* Solving with glpsol */ param->presolve = GLP_ON; glp_simplex(Prob,param); param->presolve = GLP_OFF; currResult = glp_get_obj_val(Prob); /* Local search using the first increase */ for( i = 0 ; i < n-1 ; ++i ) { /* Swap two adjacent planes */ swapConstraint(Prob,i,solution,0); glp_simplex(Prob,param); /* Check for improvements */ if( GLP_OPT == glp_get_status(Prob) && glp_get_obj_val(Prob) < currResult ) { currResult = glp_get_obj_val(Prob); /* Changing the solution */ int swp; swp = solution[i]; solution[i] = solution[i+1]; solution[i+1] = swp; /* Restarting */ i = -1; } else swapConstraint(Prob,i,solution,1); } /* Checking improvements */ if( bestResult > currResult ) { bestResult = currResult; for( i = 0 ; i < n ; ++i ) planes[solution[i]].pos = i; } /* Choosing alpha */ alpha = rand()%(maxAlpha+1); /* Is our time up? */ time(&curr); if( difftime(curr,start) > maxTime ) break; } /* Print Answer */ printResult(Prob, stdout); if( outFile ) { printResult(Prob, outFile); fclose(outFile); } return 0; }
static PyObject* LPX_solver_simplex(LPXObject *self, PyObject *args, PyObject *keywds) { #if GLPK_VERSION(4, 18) glp_smcp cp; // Set all to GLPK defaults, except for the message level, which // inexplicably has a default "verbose" setting. glp_init_smcp(&cp); cp.msg_lev = GLP_MSG_OFF; // Map the keyword arguments to the appropriate entries. static char *kwlist[] = {"msg_lev", "meth", "pricing", "r_test", "tol_bnd", "tol_dj", "tol_piv", "obj_ll", "obj_ul", "it_lim", "tm_lim", "out_frq", "out_dly", "presolve", NULL}; if (!PyArg_ParseTupleAndKeywords (args, keywds, "|iiiidddddiiiii", kwlist, &cp.msg_lev, &cp.meth, &cp.pricing, &cp.r_test, &cp.tol_bnd, &cp.tol_dj, &cp.tol_piv, &cp.obj_ll, &cp.obj_ul, &cp.it_lim, &cp.tm_lim, &cp.out_frq, &cp.out_dly, &cp.presolve)) { return NULL; } cp.presolve = cp.presolve ? GLP_ON : GLP_OFF; // Do checking on the various entries. switch (cp.msg_lev) { case GLP_MSG_OFF: case GLP_MSG_ERR: case GLP_MSG_ON: case GLP_MSG_ALL: break; default: PyErr_SetString (PyExc_ValueError, "invalid value for msg_lev (LPX.MSG_* are valid values)"); return NULL; } switch (cp.meth) { case GLP_PRIMAL: case GLP_DUALP: break; #if GLPK_VERSION(4, 31) case GLP_DUAL: break; #endif default: PyErr_SetString (PyExc_ValueError, "invalid value for meth (LPX.PRIMAL, LPX.DUAL, " "LPX.DUALP valid values)"); return NULL; } switch (cp.pricing) { case GLP_PT_STD: case GLP_PT_PSE: break; default: PyErr_SetString (PyExc_ValueError, "invalid value for pricing (LPX.PT_STD, LPX.PT_PSE valid values)"); return NULL; } switch (cp.r_test) { case GLP_RT_STD: case GLP_RT_HAR: break; default: PyErr_SetString (PyExc_ValueError, "invalid value for ratio test (LPX.RT_STD, LPX.RT_HAR valid values)"); return NULL; } if (cp.tol_bnd<=0 || cp.tol_bnd>=1) { PyErr_SetString(PyExc_ValueError, "tol_bnd must obey 0<tol_bnd<1"); return NULL; } if (cp.tol_dj<=0 || cp.tol_dj>=1) { PyErr_SetString(PyExc_ValueError, "tol_dj must obey 0<tol_dj<1"); return NULL; } if (cp.tol_piv<=0 || cp.tol_piv>=1) { PyErr_SetString(PyExc_ValueError, "tol_piv must obey 0<tol_piv<1"); return NULL; } if (cp.it_lim<0) { PyErr_SetString(PyExc_ValueError, "it_lim must be non-negative"); return NULL; } if (cp.tm_lim<0) { PyErr_SetString(PyExc_ValueError, "tm_lim must be non-negative"); return NULL; } if (cp.out_frq<=0) { PyErr_SetString(PyExc_ValueError, "out_frq must be positive"); return NULL; } if (cp.out_dly<0) { PyErr_SetString(PyExc_ValueError, "out_dly must be non-negative"); return NULL; } // All the checks are complete. Call the simplex solver. int retval = glp_simplex(LP, &cp); if (retval!=GLP_EBADB && retval!=GLP_ESING && retval!=GLP_ECOND && retval!=GLP_EBOUND && retval!=GLP_EFAIL) self->last_solver = 0; return glpsolver_retval_to_message(retval); #else int retval = lpx_simplex(LP); if (retval!=LPX_E_FAULT) self->last_solver = 0; return solver_retval_to_message(retval); #endif }
int c_simplex_sparse(int m, int n, DMAT(c), DMAT(b), DVEC(s)) { glp_prob *lp; lp = glp_create_prob(); glp_set_obj_dir(lp, GLP_MAX); int i,j,k; int tot = cr - n; glp_add_rows(lp, m); glp_add_cols(lp, n); //printf("%d %d\n",m,n); // the first n values for (k=1;k<=n;k++) { glp_set_obj_coef(lp, k, AT(c, k-1, 2)); //printf("%d %f\n",k,AT(c, k-1, 2)); } int * ia = malloc((1+tot)*sizeof(int)); int * ja = malloc((1+tot)*sizeof(int)); double * ar = malloc((1+tot)*sizeof(double)); for (k=1; k<= tot; k++) { ia[k] = rint(AT(c,k-1+n,0)); ja[k] = rint(AT(c,k-1+n,1)); ar[k] = AT(c,k-1+n,2); //printf("%d %d %f\n",ia[k],ja[k],ar[k]); } glp_load_matrix(lp, tot, ia, ja, ar); int t; for (i=1;i<=m;i++) { switch((int)rint(AT(b,i-1,0))) { case 0: { t = GLP_FR; break; } case 1: { t = GLP_LO; break; } case 2: { t = GLP_UP; break; } case 3: { t = GLP_DB; break; } default: { t = GLP_FX; break; } } glp_set_row_bnds(lp, i, t , AT(b,i-1,1), AT(b,i-1,2)); } for (j=1;j<=n;j++) { switch((int)rint(AT(b,m+j-1,0))) { case 0: { t = GLP_FR; break; } case 1: { t = GLP_LO; break; } case 2: { t = GLP_UP; break; } case 3: { t = GLP_DB; break; } default: { t = GLP_FX; break; } } glp_set_col_bnds(lp, j, t , AT(b,m+j-1,1), AT(b,m+j-1,2)); } glp_term_out(0); glp_simplex(lp, NULL); sp[0] = glp_get_status(lp); sp[1] = glp_get_obj_val(lp); for (k=1; k<=n; k++) { sp[k+1] = glp_get_col_prim(lp, k); } glp_delete_prob(lp); free(ia); free(ja); free(ar); return 0; }