Originally posted by: open_ball

Hi,

I was wondering if there is a built-up method to remove a constraint by its name in OPL? If not, what could be the best way to deal with it?

Hi,

by changing bounds of a constraint you could do that.

Let me start with https://www.ibm.com/developerworks/community/forums/html/topic?id=4b0b67f3-bfb7-4a37-aef2-887c606153ce&ps=25

 

    int nbKids=300;
    float costBus40=500;
    float costBus30=400;
     
    dvar int+ nbBus40;
    dvar int+ nbBus30;
     
    minimize
     costBus40*nbBus40  +nbBus30*costBus30;
     
    subject to
    {
     ctKids:40*nbBus40+nbBus30*30>=nbKids;
    }

    execute
    {
    writeln("nbBus40 = ",nbBus40);
    writeln("nbBus30 = ",nbBus30);
    }

    main
    {
    thisOplModel.generate();

    cplex.solve();
    thisOplModel.postProcess();

    //now we remove the constraint 300 kids need to go to the zoo
    writeln("remove the constraint ");
        
    thisOplModel.ctKids.LB=-100000;

    cplex.solve();
    thisOplModel.postProcess();

    

     

    }

gives

nbBus40 = 6
nbBus30 = 2
remove the constraint
nbBus40 = 0
nbBus30 = 0

and shows you how to remove a constraint

Many very simple examples at https://www.linkedin.com/pulse/making-decision-optimization-simple-alex-fleischer/

regards