optimization - I can not reach the array' s previous iteration values in OPL Script

Question

I have a MIP model in CPlex.

• In each iteration I use different .dat files and solve the problem.

• I hold the decision variable solution values in a multi dimensional array like "Array[iteration][i]", "i" is the decision variable's index and iteration represent the different instances(different .dat files).

• I want to reach "Array[1][i]" when "iteration = 2", it says "Array[1][i]= [a IloNumVar]".

       main{
           for(var datFile in thisOplModel.datFiles) {
           iteration+=1;
           var opl = new IloOplModel(def,cplex);       
           var data= new IloOplDataSource(datFile);
           opl.addDataSource(data);
           opl.generate(); 
           tempX[iteration]= new Array();
           tempY[iteration]= new Array();
  
           for(var i =1; i_node<=node; i ++){
  
               tempX[iteration][i]= new Array();
               tempY[iteration][i]= new Array();
  
               if (iteration==1){      
                   cplex.solve()
                   tempX[iteration][i]= opl.X[i];  
                   //When I want to print temp[1][i] values at iteration is equal to 1, it print the values.
                   writeln("tempX: ", tempX[1][i]); 
  
              }
           }       
  
           if (iteration==2){
               for(var i_node=1; i_node<=node; i_node++){  
               //When I am at iteration 2, i want to reach previous iteration values but it brings "[a IloNumVar]"  
                   writeln("tempX: ", tempX[1][i]);
               }
           }   
  
      opl.end();
  
   } 
  

  }

question from:https://stackoverflow.com/questions/65865475/i-can-not-reach-the-array-s-previous-iteration-values-in-opl-script

Answer 1

Instead of

tempX[iteration][i]= opl.X[i];

I would try

tempX[iteration][i]= opl.X[i].solutionValue;