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 querying 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.