CPLEX optimization array error in objective function-CodePudding

I am trying to optimize the below problem in CPLEX OPL. I have defined the parameters and decision variables. However, when I try to formulate the objective function and the constraints I seem to encounter a problem as I receive an error in the line of the objective function calles 'cannot use type range for int'. I am not sure what is wrong here.

Also in the constraint formulation I have a problem formulating constraints that ensure that variable I & W are balanced in between two consequative periods. CPLEX error reads operator not available for range - int.

The problem I am trying to recreate is: This is my current data file:

 time=2;

 
 // Try product =1
 
 d = [2000,1500];
 k = [5000,5000];
 h = [1,1];
 p = [300,300];
 q = [600,600];
 e = [1,1];
 c = [3,3];
 r = [4,4];

This is what I came up with so far in the model:

int Time = ...; range T=1..Time;

 // Parameters
 int d [T] = ...; // demand in period t 
 int K [T] = ...; // fixed order cost in period t 
 int h [T] = ...; // unit holding cost in period t 
 int p [T] = ...; // fixed cost of increasing WH size in period t
 int q [T] = ...; // fixed cost of increasing WH size in period t
 int e [T] = ...; // variable cost of increasing WH size in period t
 int c [T] = ...; // variable cost of decreasing WH size in period t
 int r [T] = ...;  // WH rental cost per unit in period t 
 
dvar int  x[T]; //order size in period t 
dvar int  i[T]; //inventory lvl at the end of period t 
dvar int  w[T]; // warehouse size at the end of period t 
dvar int  u[T]; // warehouse size expansion at beginning of period t 
dvar int  v[T]; // warehouse size contraction at beginning of period t 
dvar boolean y[T]; // binary variable for ordering in period t 
dvar boolean z1[T]; // binary variable for WH expansion in period t 
dvar boolean z2[T]; // binary variable for WH contraction in period t 
 
 //objecTve funcTon
dexpr int Cost = sum(t in T)(K[T]*y[T] h[T]*i1[T] p[T]*z1[T] e[T]*u[T] q[T]*z2[T] c[T]*v[T] r[T]*w1[T]);
 
minimize Cost;

//constraints

subject to {

forall(t in T) {
i[T-1]   x[T] - d[T] == i[T];


w[T-1]   u[T] - v[T] == w[T];


i[T] <= w[T];


x[T] <= d[T]*y[T];


u[T] <= d[T]*z1[T];


v[T] <= d[T]*z2[T];   

I[0]==0;   
}   
}

Could someone give me some advice on what I am doing wrong in the objective function formulation and How I can correctly formulate the constraint that I(t-1) x-d=I(t) ?

This would be very much appreciated!

CodePudding user response：

A few errors but

.mod

int Time = ...;

 range T=0..Time;

 // Parameters
 int d [T] = ...; // demand in period t 
 int K [T] = ...; // fixed order cost in period t 
 int h [T] = ...; // unit holding cost in period t 
 int p [T] = ...; // fixed cost of increasing WH size in period t
 int q [T] = ...; // fixed cost of increasing WH size in period t
 int e [T] = ...; // variable cost of increasing WH size in period t
 int c [T] = ...; // variable cost of decreasing WH size in period t
 int r [T] = ...;  // WH rental cost per unit in period t 
 
dvar int  x[T]; //order size in period t 
dvar int  i[T]; //inventory lvl at the end of period t 
dvar int  w[T]; // warehouse size at the end of period t 
dvar int  u[T]; // warehouse size expansion at beginning of period t 
dvar int  v[T]; // warehouse size contraction at beginning of period t 
dvar boolean y[T]; // binary variable for ordering in period t 
dvar boolean z1[T]; // binary variable for WH expansion in period t 
dvar boolean z2[T]; // binary variable for WH contraction in period t 
 
 //objecTve funcTon
dexpr int Cost = sum(t in T)
(K[t]*y[t] h[t]*i[t] p[t]*z1[t] e[t]*u[t] q[t]*z2[t] c[t]*v[t] r[t]*w[t]);
 
minimize Cost;

//constraints

subject to {

forall(t in T:(t-1) in T) {
i[t-1]   x[t] - d[t] == i[t];


w[t-1]   u[t] - v[t] == w[t];


i[t] <= w[t];


x[t] <= d[t]*y[t];


u[t] <= d[t]*z1[t];


v[t] <= d[t]*z2[t];   

i[0]==0;   
}   
}

.dat

 Time=2;

 
 // Try product =1
 
 d = [2000,1500];
 K = [5000,5000];
 h = [1,1];
 p = [300,300];
 q = [600,600];
 e = [1,1];
 c = [3,3];
 r = [4,4];

work fine