Originally posted by: Larelian

Hey,

I would like to sum over a limited part of the indexes of a parameter/decision variable/...
How can I do this?

F.e.:
String P = {"P1", "P2", "P3", "P4"};
int D = {1 2 3 4 5 6 7};
int A = {1 2 3 4 5 6 7};

float LOS[P][D] = [ 1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 29 20 21
22 23 24 25 26 27 28 ] ;

dvar int+ x[P][A];

Maximize sum(p in P) sum(a in A) x[p][a];

Subject to
*sum(p in P) x[p][1] * LOS[p][1] + x[p][5] * LOS[p][4] + x[p][4] * LOS[p][5] + x[p][3] * LOS[p][6] + x[p][2] * LOS[p][7] <= 200;*

Can I use this expression?
How can I sum over only f.e. p = "P1" and "P2"?

Kind regards
#DecisionOptimization
#MathematicalProgramming-General

Originally posted by: SystemAdmin

You can write the first constraint as you suggested if you add parenthesis. Below is a .mod file that should answer your questions.

{string
} P = 
{
"P1", 
"P2", 
"P3", 
"P4"
}; 
{

int
} D = 
{1, 2, 3, 4, 5, 6, 7
}; 
{

int
} A = 
{1, 2, 3, 4, 5, 6, 7
};   

float LOS[P][D] = [ [ 1.0,   2.0,  3.0,  4.0,  5.0,  6.0,  7.0 ], [ 8.0,   9.0, 10.0, 11.0, 12.0, 13.0, 14.0 ], [ 15.0, 16.0, 17.0, 18.0, 29.0, 20.0, 21.0 ], [ 22.0, 23.0, 24.0, 25.0, 26.0, 27.0, 28.0 ] ] ;   dvar int+ x[P][A];   maximize sum(p in P) sum(a in A) x[p][a];   subject to 
{ 
// Your first constraint. sum(p in P) (x[p][1] * LOS[p][1] + x[p][5] * LOS[p][4] + x[p][4] * LOS[p][5] + x[p][3] * LOS[p][6] + x[p][2] * LOS[p][7]) <= 200; 
// Sum only over p=P1 or p=P2 sum(p in P : p == 
"P1" || p == 
"P2") sum(a in A) x[p][a] <= 1; 
}

Not that for questions concerning OPL you best refer to the OPL forum here.
#DecisionOptimization
#MathematicalProgramming-General

Originally posted by: Larelian

Thank you very much!
#DecisionOptimization
#MathematicalProgramming-General