set_var_branch

# set_var_branch Specifies, for the specified variable, which branch to take first in branch-and-bound algorithm. unsigned char set_var_branch(lprec *lp, int column, int branch_mode); Return Value set_var_branch returns TRUE (1) if the operation was successful. A return value of FALSE (0) indicates an error. 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 column The column number of the variable on which the mode must be set. It must be between 1 and the number of columns in the lp. branch_mode Specifies, for the specified variable, which branch to take first in branch-and-bound algorithm. Can by any of the following values:
BRANCH_CEILING (0) | Take ceiling branch first
BRANCH_FLOOR (1) | Take floor branch first
BRANCH_AUTOMATIC (2) | Algorithm decides which branch being taken first
BRANCH_DEFAULT (3) | Use the branch mode specified with set_bb_floorfirst
Remarks The set_var_branch function specifies which branch to take first in branch-and-bound algorithm. This can influence solving times considerably. Depending on the model one rule can be best and for another model another rule. The default is BRANCH_DEFAULT (3). BRANCH_DEFAULT (3) means that the branch mode specified with set_bb_floorfirst function must be used. 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, 1);
      if(lp == NULL) {
        fprintf(stderr, "Unable to create new LP model\n");
        return(1);
      }

      set_var_branch(lp, 1, BRANCH_AUTOMATIC);

      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_var_branch, set_bb_floorfirst, get_bb_floorfirst, set_var_weights, get_var_priority