Originally posted by: Sandeep.chauhan

Hi

see https://www.ibm.com/developerworks/community/forums/html/topic?id=d8d12e36-3150-4e1c-a956-d707d17f274c&ps=25

regards

Originally posted by: Sandeep.chauhan

Thanks for your precious reply. But I want all solutions which can give  same objective value value. I know my global solution as 1000 so I am not interested in the solution which gives below 1000. I want to get all other solutions which can give same 1000.

Hi,

then in the example

dvar int xy; // in order to find all solutions

dvar int x in 0..2;
dvar int y in 0..2;
    
maximize xy;

subject to
{
  x+y<=3;
    
  xy==1000*x+y;
}

execute
{
 writeln("x=",x,"   and y=",y);
}

main {
 var nbsol=0;

 thisOplModel.generate();
 while (1==cplex.solve())
 {
     thisOplModel.postProcess();
     nbsol++;
     thisOplModel.xy.UB=thisOplModel.xy.solutionValue-1;              
 }
        writeln("nb solutions = ",nbsol);
}

you could change

x+y<=3;

into

x+y==3;

regards

Originally posted by: Sandeep.chauhan

dvar int xy; // in order to find all solutions
            range I = 1..10;
            dvar int+ x[I];
            dvar int+ y[I];
                
            maximize xy;

            subject to
            {
              forall (i in I){
              x[i] + y[i] == 10;
            }              
                
              xy==sum(i in I)(x[i]+y[i]);
            }

            execute
            {
             writeln("x=",x,"   and y=",y);
            }

            main {
             var nbsol=0;

             thisOplModel.generate();
             while (1==cplex.solve())
             {
                 thisOplModel.postProcess();
                 nbsol++;
                 thisOplModel.xy.UB=thisOplModel.xy.solutionValue-1;              
             }
                    writeln("nb solutions = ",nbsol);
            }

I am getting only

x= [10 10 10 10 10 10 10 10 10 10]   and y= [0 0 0 0 0 0 0 0 0 0]
nb solutions = 1

But I am expecting other results also like

x= [0 10 10 10 10 10 10 10 10 10]   and y= [10 0 0 0 0 0 0 0 0 0]

x= [0  0 10 10 10 10 10 10 10 10]   and y= [10 10 0 0 0 0 0 0 0 0]

Please help!

Hi,

you have to change the xy formula so that you do not get the same solution.

For instance,

range I = 1..2;
            dvar int+ x[I];
            dvar int+ y[I];
            dvar float xy;
                
            maximize xy;

            subject to
            {
              forall (i in I){
              x[i] + y[i] == 10;
            }              
                
              xy==sum(i in I)(x[i]*pow(11,i));
            }

            execute
            {
             writeln("x=",x,"   and y=",y);
            }

            main {
             var nbsol=0;

             thisOplModel.generate();
             while (1==cplex.solve())
             {
                 thisOplModel.postProcess();
                 nbsol++;
                 thisOplModel.xy.UB=thisOplModel.xy.solutionValue-1;              
             }
                    writeln("nb solutions = ",nbsol);
            }

will give a result that ends with

x= [8 0]   and y= [2 10]
x= [7 0]   and y= [3 10]
x= [6 0]   and y= [4 10]
x= [5 0]   and y= [5 10]
x= [4 0]   and y= [6 10]
x= [3 0]   and y= [7 10]
x= [2 0]   and y= [8 10]
x= [1 0]   and y= [9 10]
x= [0 0]   and y= [10 10]
nb solutions = 121

which looks normal since you have 11 options for x[1] AND x[2] so 121 options

regards

Originally posted by: Sandeep.chauhan

What If I have a equation

XY = sum( i  in 1..1000)( (A[i]*B[i]) - B[i]);

Hi,

i gave an example for xy and you can change that.

The only need is that all different solutions should lead to a different xy

regards

Originally posted by: Sandeep.chauhan

what is happening with

thisOplModel.xy.UB=thisOplModel.xy.solutionValue-1; 

the goal is to get all solutions and all solution lead to different xy values

so in this line you simply say that you do not want an xy you already got

regards

Originally posted by: Sandeep.chauhan

Is there any maximum limit to obtain the solutions? Like right now I am obtaining 121 solutions but there may be other solutions lie between this 121 solutions. So how can I search them?

Originally posted by: Sandeep.chauhan

But now my solutions are more dependent on objective functions like

with xy==sum(i in I)(x[i]*pow(11,i)); I am getting 121 solutions but

with xy==sum(i in I)(x[i]*1000); I am getting different number of solutions.

But this objective function is like a dummy function for me because actual function is to maximize xy with  x[i] + y[i] == 10;