Re: [Bug-glpk] Bounds on Binary variables

[Andrew Makhorin]

> GLPK ignores these in LP files
> 

Thank you for your bug report.

To fix the bug please replace the routine parse_integer in file
glpk/src/glpcpx.c by the following one:


static void parse_integer(struct csa *csa)
{     int j, binary;
      /* parse the keyword 'general', 'integer', or 'binary' */
      if (csa->token == T_GENERAL)
         binary = 0, scan_token(csa);
      else if (csa->token == T_INTEGER)
         binary = 0, scan_token(csa);
      else if (csa->token == T_BINARY)
         binary = 1, scan_token(csa);
      else
         xassert(csa != csa);
      /* parse list of variables (may be empty) */
      while (csa->token == T_NAME)
      {  /* find the corresponding column */
         j = find_col(csa, csa->image);
         /* change kind of the variable */
         glp_set_col_kind(csa->P, j, GLP_IV);
         /* set bounds for the binary variable */
         if (binary)
#if 0 /* 07/VIII-2013 */
         {  set_lower_bound(csa, j, 0.0);
            set_upper_bound(csa, j, 1.0);
         }
#else
         {  set_lower_bound(csa, j,
               csa->lb[j] == +DBL_MAX ? 0.0 : csa->lb[j]);
            set_upper_bound(csa, j,
               csa->ub[j] == -DBL_MAX ? 1.0 : csa->ub[j]);
         }
#endif
         scan_token(csa);
      }
      return;
}