set_improve

Specifies the iterative improvement level.

void set_improve(lprec *lp, int improve);

Return Value

set_improve has no return value.

Parameters

lp

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

improve

Specifies the iterative improvement level. Can by any of the following values:

IMPROVE_NONE (0) improve none
IMPROVE_SOLUTION (1) Running accuracy measurement of solved equations based on Bx=r (primal simplex), remedy is refactorization.
IMPROVE_DUALFEAS (2) Improve initial dual feasibility by bound flips (highly recommended, and default)
IMPROVE_THETAGAP (4) Low-cost accuracy monitoring in the dual, remedy is refactorization
IMPROVE_BBSIMPLEX (8) By default there is a check for primal/dual feasibility at optimum only for the relaxed problem, this also activates the test at the node level

Remarks

The default is IMPROVE_DUALFEAS + IMPROVE_THETAGAP (6).

Example

#include <stdio.h>
#include <stdlib.h>
#include "lp_lib.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_improve(lp, IMPROVE_DUALFEAS | IMPROVE_BBSIMPLEX);

  delete_lp(lp);
  return(0);
}

lp_solve API reference

See Also make_lp, copy_lp, read_lp, read_LP, read_mps, read_freemps, read_MPS, read_freeMPS, read_XLI, get_improve