Hello. 

I want to reference to an array using the value that is assigned to a dvar. However, an error message was given by CPLEX instead - "CP cannot extract expression". What can I do to overcome the error?

Below is the codes for my problem. 

using CP;
{string} Employee = ...;
{string} Jobs = ...;
range EmpIDs = 0..card(Employee)-1;
{int} AvailSlot[EmpIDs] = ...;
range Slots = 1...10

dvar int Time[Jobs] in Slots;
dvar int Emp[Jobs] in EmpIDs;

subject to{

forall (x in Jobs) {
   Time[x] in AvailSlot[Emp[x]];}  //this constraint the assigned time slot for the job x to be one of the available time slots of the employee that is assigned with the same job x. 

}

Thanks in advance.

------------------------------
A.C.
------------------------------

#DecisionOptimization

Hi

using CP;

{string} Employee = {"A","B"};

{string} Jobs = {"K","L"};

range EmpIDs = 0..card(Employee)-1;

{int} AvailSlot[EmpIDs] = [{1,2},{2,3}];


range Slots = 1..10;


dvar int Time[Jobs] in Slots;

dvar int Emp[Jobs] in EmpIDs;

subject to{

 
forall (x in Jobs) {
   //Time[x] in AvailSlot[Emp[x]];  //this constraints the assigned time slot for the job x to be one of the available time slots of the employee that is assigned with the same job x. 
   or (j in EmpIDs) (j==Emp[x] && Time[x] in AvailSlot[j]);
}
}

assert forall (x in Jobs) 
   Time[x] in AvailSlot[Emp[x]];​

works fine

regards

PS:

I answered this at https://stackoverflow.com/questions/62016391/cplex-indexing-an-array-using-the-assigned-value-of-a-dvar/62017203#62017203
Please try to avoid posting the same question in many forums

------------------------------
ALEX FLEISCHER
------------------------------

Original Message:
Sent: Tue May 26, 2020 02:49 AM
From: Adrian chong
Subject: array indexing using dvar in constraints

Hello. 

I want to reference to an array using the value that is assigned to a dvar. However, an error message was given by CPLEX instead - "CP cannot extract expression". What can I do to overcome the error?

Below is the codes for my problem. 

using CP;
{string} Employee = ...;
{string} Jobs = ...;
range EmpIDs = 0..card(Employee)-1;
{int} AvailSlot[EmpIDs] = ...;
range Slots = 1...10

dvar int Time[Jobs] in Slots;
dvar int Emp[Jobs] in EmpIDs;

subject to{

forall (x in Jobs) {
   Time[x] in AvailSlot[Emp[x]];}  //this constraint the assigned time slot for the job x to be one of the available time slots of the employee that is assigned with the same job x. 

}

Thanks in advance.

------------------------------
A.C.
------------------------------

#DecisionOptimization