Originally posted by: MamdouhMubarak

Hi 

I am trying to test benders decomposition as implemented by cplex 12.8

I wrote the following java code to generate and annotate the variables: 

1            IloCplex.LongAnnotation benders = CPLEX.newLongAnnotation("cpxBendersPartition");
            
2            X = CPLEX.boolVarArray(Network.Links.size());

3           Y = CPLEX.numVarArray(Network.Links.size(), 0, Float.MAX_VALUE, IloNumVarType.Int);
4            for (Link Link : Network.Links.values()) {
5                if (Link.Candidate) {
6                    X[Link.Index].setName(String.format("X[%s]", Link.ID));                    
7                    CPLEX.setAnnotation(benders, X[Link.Index], 0);
8                    Y[Link.Index].setName(String.format("Y[%s]", Link.ID));
9                    CPLEX.setAnnotation(benders, Y[Link.Index], 1);

10                }
11            }

but my code is crashing at line (6) and I am getting the following error:

would appreciate any help with this.

The problem is that your variables do not appear in any constraint or objective function yet. Hence CPLEX does not know anything about them and raises that exception. You can either move setting the annotations to a place in which the variables have already been added to constraints/objective, or you can explicitly IloCplex.add() the variables to avoid the exception.

Originally posted by: MamdouhMubarak

Thanks Daniel!