CODEWITHSUNDEEP
javacplex
jjlema
jjlema

Reputation: 850

How to obtain all IloNumVar from IloModeler or IloCplex

we have a client who gives us a IloModeler and we use that to solve the optimization problem doing this:

IloCplex cplex = new IloCplex();
cplex.setModel(IloModeler);

and, at the end we would like to return to the client a map with all IloNumVar and their value: Map<IloNumVar, Double>.

But the issue is: How can we obtain from the original IloModeler the list of all IloNumVar in order to see their value using the function cplex.getValue(IloNumVar)?

Upvotes: 0

Views: 170

Answers (1)

Alex Fleischer
Alex Fleischer

Reputation: 10059

java.util.Iterator iterator() This method returns an iterator that traverses the objects in the model.

For example with the zoo example

 IloCplex cplexBus = new IloCplex();// decision variables
 IloNumVar nbbus40 = cplexBus.numVar(0, 10000,IloNumVarType.Int,"var nbBus40"); 
 IloNumVar nbbus30 = cplexBus.numVar(0, 10000,IloNumVarType.Int,"var nbBus30");// move at least 300 kids to the zoo
 cplexBus.add(nbbus40);
 cplexBus.add(nbbus30);

 cplexBus.addGe(cplexBus.sum(cplexBus.prod(40,nbbus40), cplexBus.prod(30,nbbus30)),300);// objective : minimize cost = 500*nbbus40+400*nbBus30
 cplexBus.addMinimize(cplexBus.sum(cplexBus.prod(500,nbbus40), cplexBus.prod(400,nbbus30)));cplexBus.solve();System.out.println("nbbus40 : "  +cplexBus.getValue(nbbus40) );
  System.out.println("nbbus30 : "  +cplexBus.getValue(nbbus30) );

  java.util.Iterator it = cplexBus.iterator();
  while (it.hasNext()) {
    Object o = it.next();
    if (o instanceof IloNumVar) {
      System.out.print("Variable :"+((IloNumVar)o).getName()+"\n");
    }
  }

gives

 [java] nbbus40 : 6.0
 [java] nbbus30 : 2.0
 [java] Variable :var nbBus40
 [java] Variable :var nbBus30

Upvotes: 1

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