Originally posted by: SystemAdmin

Hi,everyone.my question is like this:
I want to do something like the this:
decide[i]j+1 + ... + decide[i]j + dur_time == dur_time

maybe you could write code as following:
INumExpr sum = cplex.NumExpr();
for (int k = 1; k <= dur_time; ++k)
sum = cplex.Sum(sum, decide[i]j + k;
// sum is now decide[i]j+1 + ... + decide[i]j + dur_time
cplex.AddEq(sum, dur_time);

Is there some method in Cplex.net that make the sum directly? just like @sum using in Lingo
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Hi,everyone.my question is like this:
I want to do something like the this:
decide[i]j+1 + ... + decide[i]j + dur_time == dur_time

maybe you could write code as following:
INumExpr sum = cplex.NumExpr();
for (int k = 1; k <= dur_time; ++k)
sum = cplex.Sum(sum, decide[i]j + k);
// sum is now decide[i]j+1 + ... + decide[i]j + dur_time
cplex.AddEq(sum, dur_time);

Is there some method in Cplex.net that make the sum directly? just like @sum using in Lingo
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Try Cplex.ScalProd. This allows you to build the scalar product of two vectors and may be helpful here.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Thanks a lot!
System.Console.WriteLine(" Minimun cost= " + cplex.ObjValue);
In this way,you can print the result of the ObjValue.
If i want to print the product of the ObjValue and 1000，which method can i use??

I try it like following,but it is wrong.
System.Console.WriteLine(" Minimun cost= " +cplex.scal(cplex.ObjValue,1000));
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

> If i want to print the product of the ObjValue and 1000，which method
> can i use??
> I try it like following,but it is wrong.
> System.Console.WriteLine(" Minimun cost= "
> +cplex.scal(cplex.ObjValue,1000));

You could simply multiply the 1000 and cplex.ObjValue (which returns a double value) as such:

System.Console.WriteLine("Minimum cost = " + cplex.ObjValue * 1000);

The cplex.ScalProd methods and such are useful for creating expressions during model building. Once the model is built and solved, simple multiplication would work.
#CPLEXOptimizers
#DecisionOptimization