Originally posted by: SystemAdmin

[dgravot@noos.fr said:]

Hello,

I'm running my OPL model from JAVA and creates new variables [i]after[/i] the model has been generated.

While accessing named constraints of my OPL model, I get IloConstraintMap object that i'm able to query with related indexed "key" , such as :


IloForAllRange rangeOneFraction = (IloForAllRange) ctrOneFraction.getSub(tk).get(t);


Apparently, I'm not able to create an IloColumn on a collection of IloForAllRange objects, which is possible on the IloRange objects.  The only way that seems available is using the setLinearCoeff api :


IloNumVar FVar = cplex.numVar(0, Double.MAX_VALUE,"FVAR_"+nbColums);
IloForAllRange rangeOneFraction = (IloForAllRange) ctrOneFraction.getSub(tk).get(t);
cplex.setLinearCoef(rangeOneFraction, FVar, 1.0 );


For performance issues, however, I'd like to be able to use IloColumn instead

Is there a way to achieve that ?

Thank you
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: davidoff

Hi

Is OPL still unable to fulfill this (through JAVA/C/C# API) ?

I can see that one can query cplex.getDual on an IloForAllRange, but this is apparently still impossible to create a column with a given coefficient on such constraint, as one would do with an IloRange instead.

David Gravot
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: davidoff

I' m facing the same problem with Cplex Optimization Studio V12.2 : it seems impossible to use the IloColumn API to add new variables on a model generated by opl due to the IloForAllRange type of the constraints.

Any workaround ?

Thanks

David
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: ubrannlund

I have a related question: I am using .NET (C#) and have something similar to you.

INumVar FVar = opl.GetElement("F").AsNumVar();
IForAllRange rangeOneFraction = (IForAllRange) opl.GetElement("rangeOneFraction").AsConstraint();
However, I would like to get the coefficient of the variable FVar in constraint rangeOneFraction, i.e. something like:

double coeff = cplex.getLinearCoef(rangeOneFraction, FVar);

How do I do that?
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

> INumVar FVar = opl.GetElement("F").AsNumVar();
> IForAllRange rangeOneFraction = (IForAllRange)
> opl.GetElement("rangeOneFraction").AsConstraint();
> However, I would like to get the coefficient of the variable FVar in
> constraint rangeOneFraction, i.e. something like:
> double coeff = cplex.getLinearCoef(rangeOneFraction, FVar);

If rangeOneFraction is just one constraint and not a range of constraints (say in a forall block), then you could use something like the following:

INumVar FVar = opl.GetElement("F").AsNumVar();
IRange rangeOneFraction = (IRange)opl.GetElement("rangeOneFraction").AsConstraint();
ILinearNumExpr expr = (ILinearNumExpr)rangeOneFraction.Expr;
ILinearNumExprEnumerator exprEnum = expr.GetLinearEnumerator();
while (exprEnum.MoveNext())
{
  if (exprEnum.NumVar.Equals((object)FVar))
  {
    double coeff = exprEnum.Value;
    Console.Out.WriteLine("Coefficient of variable " + FVar.Name + " in "+rangeOneFraction+" = " + coeff);
  }
}

#DecisionOptimization
#OPLusingCPLEXOptimizer