set_do_presolve

Specifies if a presolve must be done before solving.

void set_do_presolve(lprec *lp, short do_presolve);

Return Value

set_do_presolve has no return value.

Parameters

Pointer to previously created lp model. See return value of make_lp, copy_lp, read_lp, read_lp_file, read_LP, read_mps, read_MPS

do_presolve

TRUE or FALSE. Do presolve or not.

Remarks

The set_do_presolve function specifies if a presolve must be done before solving. Presolve looks at the model and tries to simplify it so that solving times are shorter. For example a constraint on only one variable is converted to a bound on this variable (and the constraint is deleted). Note that the model dimensions can change because of this, so be careful with this. Both rows and columns can be deleted by the presolve.
The default is not (FALSE) doing a presolve.

Example

#include <stdio.h>
#include <stdlib.h>
#include "lpkit.h"

int main(void)
{
  lprec *lp;

  /* Create a new LP model */
  lp = make_lp(0, 0);
  if(lp == NULL) {
    fprintf(stderr, "Unable to create new LP model\n");
    return(1);
  }

  set_do_presolve(lp, TRUE);

  delete_lp(lp);
  return(0);
}

lp_solve API reference