Setting solution pool options

To change the gap tolerance, the number of solutions stored, and the criteria on which solutions are substituted for others when the pool has reached its maximal capacity.

When you activate the Populate solution pool option, you can use the other options of the Mixed Integer Programming > Solution pool page to change the gap tolerance, the number of solutions stored, and the criteria on which solutions are substituted for others when the pool has reached its maximal capacity.

You can also set a limit to the number of solutions generated by the populate phase. In the tree on the left, select the Mixed Integer Programming > Solution pool. Then modify the value for Limit on number of solutions kept in pool.

As an example:

  1. Set the Basic Configuration as the default run configuration.
  2. Create a settings file and drag it to the Basic Configuration.
  3. In the settings file, select Mixed Integer programming > Solution pool from the tree on the left. Check the Populate solution pool box and set the value of Limit on number of solutions kept in pool to 3. Then execute the run configuration.

    The Problem Browser displays only 3 feasible solutions.

  4. Click the Reset button Reset button to restore the Limit on number of solutions kept in pool to its default value, then set the Solution pool intensity option to Aggressive and execute again.

    The execution yields many more solutions.

    Note:

    Other parameters may also have an effect on the solution pool, just as they affect MIP optimization or feasibility generally. See CPLEX parameters and OPL parameters in Mathematical programming options for more information.

    See also the part dedicated to the solution pool in the CPLEX Optimizer User’s Manual, in particular to understand the difference between collecting solutions and populating the pool.