CODEWITHSUNDEEP
mathoptimizationgams-mathindustrial
iman
iman

Reputation: 11

How can I write a loop like this equation in GAMS?

I tend to write some codes in GAMS that include a loop that exclude some indices ,how can I write some a loop like with exception?

u("p1","j1")*o1("p1","j2") - sum(t,v("p1","j1",t)*I1("p1","j2",t))=l=0;  
u("p1","j1")*o1("p1","j3") - sum(t,v("p1","j1",t)*I1("p1","j3",t))=l=0;

in these equations u , o together and also v,I1 together have different indices j; how can write this loop?

Upvotes: 0

Views: 654

Answers (1)

Martin Bonde
Martin Bonde

Reputation: 556

You can use a loop, but probably a better solution is to limit the equations to the right combination of sets. In any case it can be done using alias of the sets and the SameAs operator.

Alias(p,pp);
Alias(j,jj);

E_myEquation(p,j,pp,jj)  $(not (SameAs(p,pp) and SameAs(j,jj)))..
    u(p,j)*o1(pp,jj) - sum(t, v(p,j,t)*I1(pp,jj,t)) =l= 0;

This defines the equation for all combinations of (p,j) with itself, except for (p,j)==(p,j).

I hope I have understood the request correctly, but otherwise you can probably figure out the exact implementation you want, using the Alias and SameAs functions.

Upvotes: 1

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