is_anti_degen

Returns if the degeneracy rule specified in testmask is active.

unsigned char is_anti_degen(lprec *lp, int testmask);

Return Value

is_anti_degen returns TRUE or FALSE.

Parameters

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

testmask

ANTIDEGEN_NONE (0)	No anti-degeneracy handling
ANTIDEGEN_FIXEDVARS (1)	Check if there are equality slacks in the basis and try to drive them out in order to reduce chance of degeneracy in Phase 1
ANTIDEGEN_COLUMNCHECK (2)
ANTIDEGEN_STALLING (4)
ANTIDEGEN_NUMFAILURE (8)
ANTIDEGEN_LOSTFEAS (16)
ANTIDEGEN_INFEASIBLE (32)
ANTIDEGEN_DYNAMIC (64)
ANTIDEGEN_DURINGBB (128)
ANTIDEGEN_RHSPERTURB (256)	Perturbation of the working RHS at refactorization
ANTIDEGEN_BOUNDFLIP (512)	Limit bound flips that can sometimes contribute to degeneracy in some models

Remarks

The is_anti_degen function returns a flag if the degeneracy rule specified in testmask is active.

Example

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

int main(void)
{
  lprec *lp;
  unsigned char anti_degen;

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

  anti_degen = is_anti_degen(lp, ANTIDEGEN_FIXEDVARS | ANTIDEGEN_PERTURB); /* Will return FALSE */

  delete_lp(lp);
  return(0);
}

lp_solve API reference