Originally posted by: MachexC

Hi everyone,

I have a S variable it is declared as follows:

tuple  Product_cities {
 int product;
 string cities;
 int time;

}

{Product_cities} Product_cities_s   = ...;

dvar float+ S[<p,j,t> in Product_cities_s];

Because each type of product will be sold through pairs of cities at each period is different as in Excel file. For example, Product 1 will be sold from Saigon to Cantho in period of 1. However I would like to get variable S in the opposite city pair.

S (1, Cantho, 1)= S (1, Saigon,1)

S (2, Cantho, 1)= S (2, Saigon, 1)

S (3, Soctrang, 2) = S(3, Baclieu,2)

....

I do not know how to write in OPL such results. Do you have any suggestions how to resolve this issue?

Mac

Hi,

you could try to copy your set into a new set

tuple  Product_cities {
 int product;

int time;
 string cities;
 

}

sorted {Product_cities} Product_cities_s2   =

So that tuples would be sorted first according to product and then time

regards