Originally posted by: ShaCplex

Dear Alex sir,

Can I add a user cut / lazy constraint in my OPL model (CPLEX IDE)?

Could you please help me to know how it is done?

Regards,

shahul

Hi,

could

http://www-01.ibm.com/support/docview.wss?uid=swg21681643

help ?

regards

Originally posted by: ShaCplex

Thank you sir!

Regards,

shahul

Hi,

but you may add constraints by modifying empty constraints like:

dvar float+ Gas;
dvar float+ Chloride;

maximize
  40 * Gas + 50 * Chloride;
subject to {
  ctMaxTotal:     
    Gas + Chloride <= 50;
  ctMaxTotal2:    
    3 * Gas + 4 * Chloride <= 180;
  ctMaxChloride:  
    Chloride <= 40;
   ctEmpty:
     Gas<=infinity;
}
 
 main
 {
   thisOplModel.generate();
   cplex.solve();
   
   // let us add the constraint Chloride-Gas<=5;
   writeln(thisOplModel.Gas," ",thisOplModel.Chloride);
   thisOplModel.ctEmpty.UB=5;
   thisOplModel.ctEmpty.setCoef(thisOplModel.Gas,-1);
   thisOplModel.ctEmpty.setCoef(thisOplModel.Chloride,1);
   
   cplex.solve();
   writeln(thisOplModel.Gas," ",thisOplModel.Chloride);
   
 }

But in general to do that you have to book a set of empty constraints that you will then modify.

Or if you accept to generate again yoyu may do like the example in CPLEX_Studio127\opl\examples\opl\models\TravelingSalesmanProblem

regards

Originally posted by: ShaCplex

Thank you sir...I shall go through the example

Regards,

shahul