Search found 14 matches

by gamsadmin
4 months ago
Forum: Solvers
Topic: Different solutions with MCP and NLP formulation
Replies: 1
Views: 843

Different solutions with MCP and NLP formulation

Hi I am running the famous dice problem from entropy econometrics. I formulated an NLP and an MCP model (Goland, Judge, Miller, Maximum Entropy Econometrics, Chapter 2). If I assume that the average of dice throws is 2, I get the same distribution for the probabilities. If I choose 1.5 as the averag...
by gamsadmin
9 months ago
Forum: Archive Google Group
Topic: MCP solver Infeasible
Replies: 6
Views: 1406

Re: MCP solver Infeasible

Then you run the model that solves for L and then you just write for the second model L.FX(t) = L.L(t); (you might want to use a result parameter to do this resultsL(t) = L.L(t); L.FX(t) = resultsL(t); Be aware that a variable is fixed for all model solves after the fixture. If you want to "unfix" t...
by gamsadmin
1 year ago
Forum: Syntax
Topic: Benchmark checked with iterlim=0 but GAMS does not find solution with iterlim>0
Replies: 7
Views: 1451

Re: Benchmark checked with iterlim=0 but GAMS does not find solution with iterlim>0

Hi JM It seems your SAM is not perfectly balanced. 1E-4 shows that there are balance problems. The solver tries to find a solution with the maximum infeasibility below the tolerance level (something like 1E-7), so it can't find a solution because the imbalances are too big and a few imbalances can't...
by gamsadmin
2 years ago
Forum: Syntax
Topic: Infeasible solution for Hydro Optimization Problem
Replies: 1
Views: 727

Re: Infeasible solution for Hydro Optimization Problem

Hi If you check your output, you will see that two of the energylim equations are limited. You limit the total production by P4capacity, so there be at least enough capacity to produce energy(g). However, There is no feasible solution because the maximum capacity is less than the demand Cheers Renge...
by gamsadmin
2 years ago
Forum: Modeling
Topic: Private ''help'' for academic purposes :-)
Replies: 2
Views: 892

Re: Private ''help'' for academic purposes :-)

Sure, if you write me some papers so that I will receive the Nobel price in a few years.
Cheers
Renger
by gamsadmin
2 years ago
Forum: Modeling
Topic: Traffic constraint
Replies: 1
Views: 625

Re: Traffic constraint

by gamsadmin
2 years ago
Forum: Tools
Topic: Reading Data from Excel , except some Cells
Replies: 6
Views: 1587

Re: Reading Data from Excel , except some Cells

Hi
For this you can use gdxxrw (there is a comprehensive documentation with lots of examples: https://www.gams.com/latest/docs/T_GDXXRW.html ). If there is no value in the spread sheet, this is no problem.
Cheers
Renger
by gamsadmin
2 years ago
Forum: API
Topic: Solvers error when calling from MatLab
Replies: 7
Views: 3878

Re: Solvers error when calling from MatLab

Hi It would be more useful if you attach the model you are trying to solve then letting us go through 500 lines looking for an error message. And: you could also have done what Fred and I suggested: run a simple gams file with option subsystems And show the output in your post to see if Couenne is i...
by gamsadmin
2 years ago
Forum: Syntax
Topic: relational operators within GAMS
Replies: 6
Views: 2960

Re: relational operators within GAMS

You could use a mapping set P /P01 * P08/ Jn /Jn01 * Jn10/ Jm /Jm01 * Jm10/ mapN_M(Jn,Jm) /#Jn:#Jm/; display mapN_M; parameters p1(P,Jm) p2(P,Jn); p2(P,Jn) = uniform(0,10); loop((jn,jm)$mapN_M(jn,jm), p1(P,jm) = p2(P,jn); ); display p1, p2; For information on the mapping, see [url]https://www.gams.c...
by gamsadmin
2 years ago
Forum: Syntax
Topic: Change Working Directory of GAMS
Replies: 1
Views: 2492

Re: Change Working Directory of GAMS

Hi Barsssk You could use a setlocal or setglobal parameter at the beginning of your file. For example, if you want to have all your files in the directory results, which is below your model directory, I add: $setglobal results .\results\ * Send to results directory execute_unload "%results%myresults...