GAMS World Forum

Correct. I did not see the declaration "Positive variables f(i,p1)". Change this to "Positive variables f(i,i)". Since you use the variable f only over p1 there is no difference.

-Michael

Here is only the loop with the random selection of p1:

Code: Select all

scalar adr;
loop(k,
  option clear=p1;
  while(card(p1)<>50, adr = UniformInt(0,99); loop(i$(ord(i)=1), p1(i+adr) = yes));
  solve m using nlp minimizing z1;
);

-Michael

Why does the solution proposed in my previous answer not work for you? -Michael

If you already have a loop, copy the solution into a report parameter with an additional index (the loop index) and then export the GDX/Excel:

Code: Select all

...
set s / s1*s10/; parameter xl(s,i,j);
loop(s,
   solve mymodel min z us lp;
   xl(s,i,j) = x.l(i,j);
);
execute_unload 'allsol', xl;

-Michael

I think the second term in the objective needs a set of ():

Code: Select all

amac.. z =e= sum((p,s), M(s)*(0.056195*(15000*Hpompalanan(p,s)/6))- (Edr(s)*G(s)-Edr(s)*Mdagitim(s)));

-Michael

A MIP solver can often detect the infeasibility of an instance in the presolve step. This goes usually very quickly. If the infeasiblity cannot be determined by presolve and the underlying LP relaxations are feasible than B&C kicks in and this can take a long time. Theoretically, determining if ...

First solve as rMIP (message "Model has an unbounded ray") and then set a bound on the objective to prevent unboundedness (Gamma.lo = -1e6;) now check your runaway variables (Pj h1 .Microturbine) and see why this variable is not bounded by your logic. Fix it!

-Michael

Your GAMS program compiles and executes. It creates an LP that even solves to optimality. You say that the objective does not make sense. You are the only one who can debug this. What do you expect? Why does the model not give you the answers you want. This is called model debugging and requires a d...

You correctly pick the i=5 with $(ord(i)=6. Why do you expect that the ord(t) starts with 0? If you want the t "value", then either use (ord(t)-1) or t.val:

Code: Select all

obj(i)$(i.val=5).. Z =e= sum(t, x(i,t)*t.val);

-Michael

Just add them as columns:

Code: Select all

fuel,scen,2017,2018
Gas1,Scen1,9.79,10.01
Gas1,Scen2,9.79,10.02
Gas1,Scen3,9.89,10.03
...

-Michael

GAMS World Forum

Search found 1038 matches

Re: How to create a random subset with/without replacement and run model multiple times

Re: How to create a random subset with/without replacement and run model multiple times

Re: variety of solutions in one GDX/Excel Sheet

Re: variety of solutions in one GDX/Excel Sheet

Re: Water pump scheduling Model

Re: GAMS takes a long time to return infeasibility for a certain parameter

Re: Dual infeasible due to empty column 'Gamma'.

Re: Water pump scheduling Model

Re: coefficient mismatch

Re: Saving result on MAC