int main(void)
{ LPX *lp;
int ia[1+1000], ja[1+1000];
double ar[1+1000], Z, x1, x2, x3;
s1: lp = lpx_create_prob();
s2: lpx_set_prob_name(lp, "sample");
s3: lpx_set_obj_dir(lp, LPX_MAX);
s4: lpx_add_rows(lp, 3);
s5: lpx_set_row_name(lp, 1, "p");
s6: lpx_set_row_bnds(lp, 1, LPX_UP, 0.0, 100.0);
s7: lpx_set_row_name(lp, 2, "q");
s8: lpx_set_row_bnds(lp, 2, LPX_UP, 0.0, 600.0);
s9: lpx_set_row_name(lp, 3, "r");
s10: lpx_set_row_bnds(lp, 3, LPX_UP, 0.0, 300.0);
s11: lpx_add_cols(lp, 3);
s12: lpx_set_col_name(lp, 1, "x1");
s13: lpx_set_col_bnds(lp, 1, LPX_LO, 0.0, 0.0);
s14: lpx_set_obj_coef(lp, 1, 10.0);
s15: lpx_set_col_name(lp, 2, "x2");
s16: lpx_set_col_bnds(lp, 2, LPX_LO, 0.0, 0.0);
s17: lpx_set_obj_coef(lp, 2, 6.0);
s18: lpx_set_col_name(lp, 3, "x3");
s19: lpx_set_col_bnds(lp, 3, LPX_LO, 0.0, 0.0);
s20: lpx_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: lpx_load_matrix(lp, 9, ia, ja, ar);
s31: lpx_simplex(lp);
s32: Z = lpx_get_obj_val(lp);
s33: x1 = lpx_get_col_prim(lp, 1);
s34: x2 = lpx_get_col_prim(lp, 2);
s35: x3 = lpx_get_col_prim(lp, 3);
s36: printf("\nZ = %g; x1 = %g; x2 = %g; x3 = %g\n", Z, x1, x2, x3);
s37: lpx_delete_prob(lp);
return 0;
}
static int find_col(struct dsa *dsa, char *name)
{ /* find column by its symbolic name */
int j;
j = lpx_find_col(dsa->lp, name);
if (j == 0)
{ /* not found; create new column */
j = lpx_add_cols(dsa->lp, 1);
lpx_set_col_name(dsa->lp, j, name);
/* enlarge auxiliary arrays, if necessary */
if (dsa->n_max < j)
{ int n_max = dsa->n_max;
int *map = dsa->map;
int *ind = dsa->ind;
double *val = dsa->val;
double *lb = dsa->lb;
double *ub = dsa->ub;
dsa->n_max += dsa->n_max;
dsa->map = xcalloc(1+dsa->n_max, sizeof(int));
memset(&dsa->map[1], 0, dsa->n_max * sizeof(int));
memcpy(&dsa->map[1], &map[1], n_max * sizeof(int));
xfree(map);
dsa->ind = xcalloc(1+dsa->n_max, sizeof(int));
memcpy(&dsa->ind[1], &ind[1], n_max * sizeof(int));
xfree(ind);
dsa->val = xcalloc(1+dsa->n_max, sizeof(double));
memcpy(&dsa->val[1], &val[1], n_max * sizeof(double));
xfree(val);
dsa->lb = xcalloc(1+dsa->n_max, sizeof(double));
memcpy(&dsa->lb[1], &lb[1], n_max * sizeof(double));
xfree(lb);
dsa->ub = xcalloc(1+dsa->n_max, sizeof(double));
memcpy(&dsa->ub[1], &ub[1], n_max * sizeof(double));
xfree(ub);
}
dsa->lb[j] = +DBL_MAX, dsa->ub[j] = -DBL_MAX;
}
return j;
}
int GLPKLoadVariables(MFAVariable* InVariable, bool RelaxIntegerVariables,bool UseTightBounds) {
if (GLPKModel == NULL) {
FErrorFile() << "Could not add variable because GLPK object does not exist." << endl;
FlushErrorFile();
return FAIL;
}
int NumColumns = lpx_get_num_cols(GLPKModel);
if (InVariable->Index >= NumColumns) {
lpx_add_cols(GLPKModel, 1);
string Name = GetMFAVariableName(InVariable);
char* Temp = new char[Name.length()+1];
strcpy(Temp,Name.data());
lpx_set_col_name(GLPKModel,InVariable->Index+1,Temp);
}
double LowerBound = InVariable->LowerBound;
double UpperBound = InVariable->UpperBound;
if (UseTightBounds) {
LowerBound = InVariable->Min;
UpperBound = InVariable->Max;
}
if (LowerBound != UpperBound) {
lpx_set_col_bnds(GLPKModel, InVariable->Index+1, LPX_DB, InVariable->LowerBound, InVariable->UpperBound);
} else {
lpx_set_col_bnds(GLPKModel, InVariable->Index+1, LPX_FX, InVariable->LowerBound, InVariable->UpperBound);
}
if (InVariable->Binary && !RelaxIntegerVariables) {
lpx_set_class(GLPKModel, LPX_MIP);
lpx_set_col_kind(GLPKModel, InVariable->Index+1,LPX_IV);
}
return SUCCESS;
}
LPX *lpx_extract_prob(void *_mpl)
{ MPL *mpl = _mpl;
LPX *lp;
int m, n, i, j, t, kind, type, len, *ind;
double lb, ub, *val;
/* create problem instance */
lp = lpx_create_prob();
/* set problem name */
lpx_set_prob_name(lp, mpl_get_prob_name(mpl));
/* build rows (constraints) */
m = mpl_get_num_rows(mpl);
if (m > 0) lpx_add_rows(lp, m);
for (i = 1; i <= m; i++)
{ /* set row name */
lpx_set_row_name(lp, i, mpl_get_row_name(mpl, i));
/* set row bounds */
type = mpl_get_row_bnds(mpl, i, &lb, &ub);
switch (type)
{ case MPL_FR: type = LPX_FR; break;
case MPL_LO: type = LPX_LO; break;
case MPL_UP: type = LPX_UP; break;
case MPL_DB: type = LPX_DB; break;
case MPL_FX: type = LPX_FX; break;
default: insist(type != type);
}
if (type == LPX_DB && fabs(lb - ub) < 1e-9 * (1.0 + fabs(lb)))
{ type = LPX_FX;
if (fabs(lb) <= fabs(ub)) ub = lb; else lb = ub;
}
lpx_set_row_bnds(lp, i, type, lb, ub);
/* warn about non-zero constant term */
if (mpl_get_row_c0(mpl, i) != 0.0)
print("lpx_read_model: row %s; constant term %.12g ignored",
mpl_get_row_name(mpl, i), mpl_get_row_c0(mpl, i));
}
/* build columns (variables) */
n = mpl_get_num_cols(mpl);
if (n > 0) lpx_add_cols(lp, n);
for (j = 1; j <= n; j++)
{ /* set column name */
lpx_set_col_name(lp, j, mpl_get_col_name(mpl, j));
/* set column kind */
kind = mpl_get_col_kind(mpl, j);
switch (kind)
{ case MPL_NUM:
break;
case MPL_INT:
case MPL_BIN:
lpx_set_class(lp, LPX_MIP);
lpx_set_col_kind(lp, j, LPX_IV);
break;
default:
insist(kind != kind);
}
/* set column bounds */
type = mpl_get_col_bnds(mpl, j, &lb, &ub);
switch (type)
{ case MPL_FR: type = LPX_FR; break;
case MPL_LO: type = LPX_LO; break;
case MPL_UP: type = LPX_UP; break;
case MPL_DB: type = LPX_DB; break;
case MPL_FX: type = LPX_FX; break;
default: insist(type != type);
}
if (kind == MPL_BIN)
{ if (type == LPX_FR || type == LPX_UP || lb < 0.0) lb = 0.0;
if (type == LPX_FR || type == LPX_LO || ub > 1.0) ub = 1.0;
type = LPX_DB;
}
if (type == LPX_DB && fabs(lb - ub) < 1e-9 * (1.0 + fabs(lb)))
{ type = LPX_FX;
if (fabs(lb) <= fabs(ub)) ub = lb; else lb = ub;
}
lpx_set_col_bnds(lp, j, type, lb, ub);
}
/* load the constraint matrix */
ind = ucalloc(1+n, sizeof(int));
val = ucalloc(1+n, sizeof(double));
for (i = 1; i <= m; i++)
{ len = mpl_get_mat_row(mpl, i, ind, val);
lpx_set_mat_row(lp, i, len, ind, val);
}
/* build objective function (the first objective is used) */
for (i = 1; i <= m; i++)
{ kind = mpl_get_row_kind(mpl, i);
if (kind == MPL_MIN || kind == MPL_MAX)
{ /* set objective name */
lpx_set_obj_name(lp, mpl_get_row_name(mpl, i));
/* set optimization direction */
lpx_set_obj_dir(lp, kind == MPL_MIN ? LPX_MIN : LPX_MAX);
/* set constant term */
lpx_set_obj_coef(lp, 0, mpl_get_row_c0(mpl, i));
/* set objective coefficients */
len = mpl_get_mat_row(mpl, i, ind, val);
for (t = 1; t <= len; t++)
lpx_set_obj_coef(lp, ind[t], val[t]);
break;
}
}
/* free working arrays */
ufree(ind);
ufree(val);
/* bring the problem object to the calling program */
return lp;
}
