void npp_del_row(NPP *npp, NPPROW *row)
{ /* remove row from the current problem */
#if 0 /* 23/XII-2009 */
NPPAIJ *aij;
#endif
if (row->name != NULL)
dmp_free_atom(npp->pool, row->name, strlen(row->name)+1);
#if 0 /* 23/XII-2009 */
while (row->ptr != NULL)
{ aij = row->ptr;
row->ptr = aij->r_next;
if (aij->c_prev == NULL)
aij->col->ptr = aij->c_next;
else
aij->c_prev->c_next = aij->c_next;
if (aij->c_next == NULL)
;
else
aij->c_next->c_prev = aij->c_prev;
dmp_free_atom(npp->pool, aij, sizeof(NPPAIJ));
}
#else
npp_erase_row(npp, row);
#endif
npp_remove_row(npp, row);
dmp_free_atom(npp->pool, row, sizeof(NPPROW));
return;
}
int npp_hidden_covering(NPP *npp, NPPROW *row)
{ /* identify hidden covering inequality */
NPPROW *copy;
NPPAIJ *aij;
struct elem *ptr, *e;
int kase, ret, count = 0;
double b;
/* the row must be inequality constraint */
xassert(row->lb < row->ub);
for (kase = 0; kase <= 1; kase++)
{ if (kase == 0)
{ /* process row lower bound */
if (row->lb == -DBL_MAX) continue;
ptr = copy_form(npp, row, +1.0);
b = + row->lb;
}
else
{ /* process row upper bound */
if (row->ub == +DBL_MAX) continue;
ptr = copy_form(npp, row, -1.0);
b = - row->ub;
}
/* now the inequality has the form "sum a[j] x[j] >= b" */
ret = hidden_covering(npp, ptr, &b);
xassert(0 <= ret && ret <= 2);
if (kase == 1 && ret == 1 || ret == 2)
{ /* the original inequality has been identified as hidden
covering inequality */
count++;
#ifdef GLP_DEBUG
xprintf("Original constraint:\n");
for (aij = row->ptr; aij != NULL; aij = aij->r_next)
xprintf(" %+g x%d", aij->val, aij->col->j);
if (row->lb != -DBL_MAX) xprintf(", >= %g", row->lb);
if (row->ub != +DBL_MAX) xprintf(", <= %g", row->ub);
xprintf("\n");
xprintf("Equivalent covering inequality:\n");
for (e = ptr; e != NULL; e = e->next)
xprintf(" %sx%d", e->aj > 0.0 ? "+" : "-", e->xj->j);
xprintf(", >= %g\n", b);
#endif
if (row->lb == -DBL_MAX || row->ub == +DBL_MAX)
{ /* the original row is single-sided inequality; no copy
is needed */
copy = NULL;
}
else
{ /* the original row is double-sided inequality; we need
to create its copy for other bound before replacing it
with the equivalent inequality */
copy = npp_add_row(npp);
if (kase == 0)
{ /* the copy is for upper bound */
copy->lb = -DBL_MAX, copy->ub = row->ub;
}
else
{ /* the copy is for lower bound */
copy->lb = row->lb, copy->ub = +DBL_MAX;
}
/* copy original row coefficients */
for (aij = row->ptr; aij != NULL; aij = aij->r_next)
npp_add_aij(npp, copy, aij->col, aij->val);
}
/* replace the original inequality by equivalent one */
npp_erase_row(npp, row);
row->lb = b, row->ub = +DBL_MAX;
for (e = ptr; e != NULL; e = e->next)
npp_add_aij(npp, row, e->xj, e->aj);
/* continue processing upper bound for the copy */
if (copy != NULL) row = copy;
}
drop_form(npp, ptr);
}
return count;
}
int npp_reduce_ineq_coef(NPP *npp, NPPROW *row)
{ /* reduce inequality constraint coefficients */
NPPROW *copy;
NPPAIJ *aij;
struct elem *ptr, *e;
int kase, count[2];
double b;
/* the row must be inequality constraint */
xassert(row->lb < row->ub);
count[0] = count[1] = 0;
for (kase = 0; kase <= 1; kase++)
{ if (kase == 0)
{ /* process row lower bound */
if (row->lb == -DBL_MAX) continue;
#ifdef GLP_DEBUG
xprintf("L");
#endif
ptr = copy_form(npp, row, +1.0);
b = + row->lb;
}
else
{ /* process row upper bound */
if (row->ub == +DBL_MAX) continue;
#ifdef GLP_DEBUG
xprintf("U");
#endif
ptr = copy_form(npp, row, -1.0);
b = - row->ub;
}
/* now the inequality has the form "sum a[j] x[j] >= b" */
count[kase] = reduce_ineq_coef(npp, ptr, &b);
if (count[kase] > 0)
{ /* the original inequality has been replaced by equivalent
one with coefficients reduced */
if (row->lb == -DBL_MAX || row->ub == +DBL_MAX)
{ /* the original row is single-sided inequality; no copy
is needed */
copy = NULL;
}
else
{ /* the original row is double-sided inequality; we need
to create its copy for other bound before replacing it
with the equivalent inequality */
#ifdef GLP_DEBUG
xprintf("*");
#endif
copy = npp_add_row(npp);
if (kase == 0)
{ /* the copy is for upper bound */
copy->lb = -DBL_MAX, copy->ub = row->ub;
}
else
{ /* the copy is for lower bound */
copy->lb = row->lb, copy->ub = +DBL_MAX;
}
/* copy original row coefficients */
for (aij = row->ptr; aij != NULL; aij = aij->r_next)
npp_add_aij(npp, copy, aij->col, aij->val);
}
/* replace the original inequality by equivalent one */
npp_erase_row(npp, row);
row->lb = b, row->ub = +DBL_MAX;
for (e = ptr; e != NULL; e = e->next)
npp_add_aij(npp, row, e->xj, e->aj);
/* continue processing upper bound for the copy */
if (copy != NULL) row = copy;
}
drop_form(npp, ptr);
}
return count[0] + count[1];
}
