Originally posted by: fahimeh

hello.

I want to define an a decision variable (a[i][j]), but when i define it, in this way

using CP;

range R=0..3;

range Rm=1..3;

range Round =1..4;

dvar int a[R][R] in 0..1;

dvar int tmp [R] in 0..1;

dvar int b[R][R] in 0..1;

minimize

sum (i,j in R) a[i][j]+b[i][j];

 

subject to {

forall( i in R){
  forall( j in R){
    c= (i+j)%4;
 
    tmp[j]=a[i][c];
    }
  forall( j in R){
      a[i][j]=tmp[j];
       }  
    }      
 forall(i in R) {

 forall (j in R){

  a[i][j]+b[i][j] >=1

   }

  }

}

 

it makes this error   " Type syntax error, unexpected ="

 

would you please tell me if i want to shift decision variable,what code i should write?

thank

#DecisionOptimization
#OPLusingCPOptimizer

Originally posted by: Philippe_Refalo

Hi Fahimeh,

OPL is a declarative langage and you can only state constraints in the suject to section. That is you cannot use = (an assignment) between variables. You have to make then equal using a constraint like x == y. In your case I believe you want to make some variables equal in the matrix a. In this case you can use direct constraints like a[i][c] == a[i][j] wihout the need for an intermediate variable (tmp). Since tmp is a mathematical variable it cannot be "reused" as in an imperative langage.

Regards

Philippe

#DecisionOptimization
#OPLusingCPOptimizer