Originally posted by: JCGar

Hello,

I have the following code and I would like to be able to evaluate a "null or empty" value in a position. I've been trying with the null function.

{int} conjuPred [h in 1..2, i in 1..5] = [  [ {} {1} {2} {2} {4} ]
                                                            [ {} {1} {} {} {} ]  ] ;

string phi = "Bad";
execute{
     if (conjunPred[1][1] == null){
              phi = "Good";
     }  
}
execute{
    writeln("Result: "+phi)
}

 ¿ What would be the correct function to be able to enter to the "if" conditional ?

Many thanks in advance.

Best Regards.

Hi

if (conjunPred[1][1].size==0)

regards

Originally posted by: JCGar

Hello,

Thank you so much, it runs fine. But I tried using the code for a restriction and it doesn't work. I get an error: a type of tuple was expected, but an int was found.

I attached a part of the code:

int nbL = 2;

range H = 1..nbL;

tuple conjPrecedesor{
    int h;   // line
    int i;   // task
    int taskP;     // task predecesor  ;
}

{int} conjPred [h in H, i in 1..5] = [  [{} {1} {2} {2} {4}]
                                                       [{} {1} {} {} {}]  ];

{conjPrecedesor} index_IPhi = { <h,i,taskP> | h in H, i in conjTask[h], taskP in conjPred[h][i] };

subject to {

  forall (h in H, u in qh[h], i in conjTask[h] : conjPred[h][i].size == 0  )      
      ST[<h,u,i>] >= cth[h]* sum(c in qh[h])(c-1) * x[<h,u,c>];                                    
      
    forall (h in H, u in qh[h], i in conjTask[h]  : conjSuce[h][i].size == 0   )         
      ST[<h,u,i>] + item(conjuntoTiempos [h][i],0) <= cth[h] * sum(c in qh[h]) c * x[<h,u,c>];

}

Regards.

Hi

in subject to you should not use JavaScript but opl so change

conjPred[h][i].size == 0

into

card(conjPred[h][i])== 0

regards

Originally posted by: JCGar

Thank you very much, it works great.

Regards.