Documentation


GRBCallback.StopOneMultiObj()

Interrupt the optimization process of one of the optimization steps in a multi-objective MIP problem without stopping the hierarchical optimization process. Only available for multi-objective MIP models and when the where member variable is not equal to GRB.Callback.MULTIOBJ (see the Callback Codes section for more information).

You would typically stop a multi-objective optimization step by quering the last finished number of multi-objectives steps, and using that number to stop the current step and move on to the next hierarchical objective (if any) as shown in the following example:

Example usage:

using Gurobi;

class callback : GRBCallback
{

  private int objcnt;
  private long starttime;

  protected override void Callback() {
    try {
      if (where == GRB.Callback.MULTIOBJ) {
        /* get current objective number */
        objcnt    = GetIntInfo(GRB.Callback.MULTIOBJ_OBJCNT);

        /* reset start time to current time */
        starttime = DateTime.Now.Ticks;

      } else if (DateTime.Now.Ticks - starttime > BIG ||
                 /* takes too long or good enough */) {
        /* stop only this optimization step */
        StopOneMultiObj(objcnt);
      }
    }
  }
}

You should refer to the section on Multiple Objectives for information on how to specify multiple objective functions and control the trade-off between them.

void StopOneMultiObj ( int objcnt )

    Arguments:

    objnum: The number of the multi-objective optimization step to interrupt. For processes running locally, this argument can have the special value -1, meaning to stop the current step.