GAMS World Forum

Hello

I have a code that does not return a solution. I'd like to know if there is a contradiction in the equations or something else preventing the solution. How can I investigate this? The code is attached for your reference.

Hmm, GAMS has many solvers. You need to be specific. Best if you attach your log file. I have attached the log of the BARON solver. As I said before, it declares the model unbounded, but that's an okay outcome in optimization (optimal, infeasible, or unbounded are the three possible outcomes of an ...

parameters.gms GAMS is very very explicit: "**** Exec Error at line 67: rPower: FUNC DOMAIN: x**y, x=0,y<0". Your line 67 looks as follows: 67 eq7 .. PH2 =e= 0.5*(RHa*PH2O)*((exp((1.635*Ifc/A)/(signpower(Tfc,1.334)))*(RHa*PH2O/Pa)**(-1))-1); There is just one term with ** in there. Lookin...

Hello
I have a code that had several errors. I fixed most of them by defining initial conditions to fix the division by zero errors and replacing some ** operators with power functions.
Now, I have domain errors that I could not fix. Please help.

bussieck wrote: ↑1 year ago Use Set not Parameter since this expects a number to be stored with a record.

Code: Select all

 Set genType(g,f)
    /
    g1.Oil-CT
    g2.Oil-CT
    g3.Coal-Steam
    g4.Coal-Steam
  /;

-Michael

Thank you very much. That resolved the issue.
I appreciate your help and support.

The trouble is that GAMS has no string valued symbols, everything is double valued or sets (with yes/no membership). So gendata(g,"Type")="Oil" does not work in GAMS. There a a couple of ways around this. You could make a set genType(g,f) (f for fuel) and then the algebra would ...

Hello Everyone, Is it possible to type a conditional statement with a string? For example, to sum the output of all generators of the same fuel type at each hour after the solve statement: units(t,"Oil") = sum(g, P.l(g,t)$(gendata(g,"Type")="Oil")); But I am getting the...

Hello Everyone, I have a parameter that stores my results as follows: report(scenario, time, "result") where scenario and time are sets I need to plot result vs time for each scenario (multi-line plot), but this cannot be done. I am getting random charts. I am plotting from the output gdx ...

Hello Everyone, I have the following code: set j /L1*L6/ k /t1*t24/ j1 /L1*L3/ j2 /L4*L6/ Table OT(j,*) p s f r L1 750 17 24 2 L2 700 15 20 3 L3 600 15 24 2 L4 400 15 24 10 L5 150 1 24 24 L6 150 16 18 3; Table c(k,*) m n t d u t1 10.1 1 22 24 1 t2 10.1 2 22 1 1 t3 10.1 3 21 2 1 t4 10.1 4 21 3 1 t5 1...

Fred wrote: ↑2 years ago Hi,

The post How do I formulate logical expressions in equations? from the FAQ may be helpful:

I hope this helps!

Fred

Thanks Fred for your reply and help.