Difference Between Variables And Paramters

Question

I am new to GAMS and am struggling to find useful tutorials online. Can someone answer me the following.....

What is the difference between Parameters and Variables. From our college session, they appear to be the same, although I imagine I am missing something.

Our first program has the following code.

Parameters
   el_supply  Price elasticity of supply in the EU
   el_dem     Price elasticity of demand in the EU
   int_supply Supply intercept in the EU
   int_dem    Demand intercept in the EU

   tp         Rate of technical progress
   chg_dem    Rate of change in demand
;


el_supply =   0.5;
el_dem    =  -0.1;






Variables
   SUPPLY        Supply of wheat in the EU (Mio t)
   DEMAND        Demand of wheat in the EU (Mio t)
   NX            Net exports of wheat in the EU (Mio t)
   PRICE         Wheat price in the EU (Euro per t)
;

score 0 · Answer 1 · answered Feb 11 '19 at 08:34

In short, parameters contain data, variables are decisions made by the optimizer.

But this was actually asked before and answered in detail here: In GAMS, what is the difference between variables and parameters?

If you are looking for a basic tutorial, you can find one here: https://www.gams.com/latest/docs/UG_Tutorial.html

Difference Between Variables And Paramters

1 Answers1