Originally posted by: ShaCplex

Dear Alex sir,

I have a query regarding the elimination of unwanted combinations in a 3D variable;

Suppose I declare my variable,

dvar boolean X [trips][trips][aircrafts];

and the parameter float Cost [t1 in trips][t2 in trips][a in aircrafts]=1000;

and I am reading the cost value from an excel sheet using,

tuple TRIPDATA {
key string tripID1;
key string tripID2;
key string aircraftID;
float cost;
}
{TRIPDATA} tripData=...;

execute
{
for(var e in tripData)
    Cost
        [trips.find(e.tripID1)]
        [trips.find(e.tripID2)]
        [aircrafts.find(e.aircraftID)]=e.cost;
}

Now, suppose if I have 10 trips and 5 aircrafts in the problem, I will have 10*10*5 = 500 variables. i.e 500  [trips][trips][aircrafts] combinations.

But I will be giving only valid,lets say 250 combinations and its cost in excel. So How can I eliminate those combinations or variables which are not there in the excel sheet?

Please help me.

Regards,

shahul

Hi,

in documentation, I suggest

IDE and OPL > Optimization Programming Language (OPL) > Language User's Manual > Introduction to OPL > Modeling tips

Sparsity

Discusses sparsity, tuples of parameters, and filtering in the context of model efficiency.