Originally posted by: mathygirl

Is it possible to perform set intersection in OPL Script? Basically, what I have in my OPL script is set1 and set2 that are read in from a model. I'd like to perform the following operation:

for(var s in set1 inter set2) {

    do something;

}

The above syntax doesn't work, and I'm wondering if something equivalent to this might work in OPL script.

While trying to solve this, I've also stumbled on another question. Is it possible to get something equivalent to a HashMap or dictionary in OPL script?

Hi,

three examples:

{int} A={1,3};
{int} B={1,2};
{int} C=A inter B;

execute
{
for(var i in C) writeln(i);
for(var i in A) if (B.contains(i)) writeln(i);

for(var i in Opl.operatorINTER(A,B))  writeln(i);
}

regards

Originally posted by: mathygirl

Thank you, this is super helpful. Is this in the documentation?

for(var i in C) writeln(i);
for(var i in A) if (B.contains(i)) writeln(i);

for(var i in Opl.operatorINTER(A,B)) writeln(i);

Originally posted by: OPLnewbie

Hey, 

I've also got a problem with sets, in this case the difference, here with my example data:

range D = 1..2;

{int} T = {1,2};

{int} ToD[D] = [{1},{1}];

Unfortunately the difference of the set doesn't work, as it puts for all Xdt a value of 0. Can anybody help?

Regards 

Hi,

maybe you get that because you do not have any objective.

If I slightly change your model into

range D = 1..2;
  int a[i in D]=10*i;

{int} T = {1,2};

{int} ToD[D] = [{1},{1}];

dvar int X[D][1..2];

maximize sum(d in D,t in 1..2) X[d][t];
subject to
{
   forall( d in D, t in ToD[d]){
          X[d][t]<= a[d];
     }
          
   forall( d in D, t in (T diff ToD[d])){
           X[d][t] == 0;
     }
   }    
 

then you get

X = [[10 0]
             [20 0]];

regards

Originally posted by: OPLnewbie

Thank you very much for the quick answer. I did have an objective function, the constraints are part of a bigger model, but indeed there was the problem. At least I do know now for sure, that it was not the diffence of sets construction.

Regards