Originally posted by: mbam

Hello,

I have two questions:

1) Is there a way to control the variables that are branched on in a MIP? For example, if there are two sets of variables, x and y, I want to give priority to x.

2) How can I output the time it took to solve to an optimality gap of 10%, 5%, 1%, and 0% in the same run?

 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi

 

1) You should use

Example:

dvar int x;

execute

{

x.priority=2;

}

 

2) You should use a main (flow control)  and do different runs with different epgap

main

{

thisOplModel.generate();

cplex.epgap=0.1;

cplex.solve();

cplex.epgap=0.05;

cplex.solve();

cplex.epgap=0.01;

cplex.solve();

cplex.epgap=0.000001;

cplex.solve();

}

regards

 

 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: mbam

Thank you very much for your reply. I will try the branching priority.

For the optimality gap, I need to be able to get the time for all those gaps within one run. I have been doing what you suggested above, but I get inconsistent results. So I need to get the time within one run. Do you have any idea how to do that?

 

#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: mbam

I am still struggling with the second question. Any help would be much appreciated.

Thank you.

#DecisionOptimization
#OPLusingCPLEXOptimizer