Originally posted by: Robscher

Hi Everyone,

I am trying to create a model which has variables over 4 dimensions. For example: Demand[a][b][c][d].
Since I am planning on running this model with multiple instances, I decided to read the according data from an Excel sheet. It works for variables in a one-dimensional array.
My problem is that I dont know how to arrange these multiple dimensions within Excel so that I can simply access them through OPL.

This is what it could like:

MOD-File:

---

int nbPeriods = ...;
range Periods = 1..nbPeriods;
int VariableOCostPeriods=...;
int DemandPeriods=...;

dvar int QuantityPeriods;

minimize
(sum( t in Periods )
( VariableOCost[t] * Quantity[t] ));

subject to {
ctWhatEverConstraint:
forall( t in Periods)
Quantity[t] >= 1.5*Demand [t];

}
##############

DAT-File:

---

SheetConnection sheet("TestMitExcel.xls");

nbPeriods from SheetRead(sheet,"B2");
VariableOCost from SheetRead(sheet,"E2:E16");
Demand from SheetRead(sheet,"F2:F16");
##############

I am grateful for any comments and ideas,
Robert
#DecisionOptimization
#OPLusingCPOptimizer

Hi,

in the OPL documentation we can read:

Use the SheetRead keyword to read spreadsheet ranges into OPL 1-D or 2-D arrays and sets

So for Demand[a][b][c][d], I suggest to have a 1-D set with 5 columns:
a,b,c,d and Demand.

You then read this set with SheetRead and turn it into an array in OPL

regards

Alex
#DecisionOptimization
#OPLusingCPOptimizer