Search found 233 matches

by Renger
6 days ago
Forum: Modeling
Topic: Execution Error : Division by zero
Replies: 3
Views: 124

Re: Execution Error : Division by zero

Hi The only equation in the model used with a division is: augm_obj.. sum(o1,dir(o1)*b(o1)) + 1e-3*sum(om1,sl(om1)/(maxobj(om1) - minobj(om1))) =e= a_objval; so, it looks like the difference between maxobj(om1) and minobj(om1) gets zero for a certain or all om1. You could rewrite the equation by add...
by Renger
1 week ago
Forum: Solvers
Topic: output the results to excel
Replies: 1
Views: 66

Re: output the results to excel

Hi Vahdi

You will find the answer in the first example of the GDXXRW documentation.

Cheers
Renger
by Renger
2 weeks ago
Forum: Solvers
Topic: *** Failure calling solver: CONOPT4 (rc=1). What does it mean?
Replies: 5
Views: 211

Re: *** Failure calling solver: CONOPT4 (rc=1). What does it means?

Hi
Conopt4, as far as I can see in the documentation, came with GAMS version 25.1. Perhaps you have an older version of GAMS.
Just try 'option nlp=conopt;' (assuming you are trying to solve an NLP problem).

CHeers
Renger
by Renger
2 weeks ago
Forum: Solvers
Topic: Various Answers
Replies: 4
Views: 157

Re: Various Answers

It sounds a little bit weird but perhaps https://www-01.ibm.com/support/docview. ... wg21399979 can explain it.
Cheers
Renger
by Renger
2 weeks ago
Forum: Archive Google Group
Topic: Terminated by solver but optimal
Replies: 3
Views: 1192

Re: Terminated by solver but optimal

You can find the option scanind in the documentation on CPLEX (https://www.gams.com/latest/docs/S_CPLEX.html). If you don't want matrix scaling the value should be -1.
Cheers
Renger
by Renger
2 weeks ago
Forum: Modeling
Topic: HELP (large variance)
Replies: 2
Views: 1247

Re: HELP (large variance)

Hi You haven't checked your SAM. The SAM shows imbalances parameter checkrow(v), checkcol(u), checkbal(u); checkrow(u) = sum(v, sam(v,u)); checkcol(v) = sum(u, sam(v,u)); checkbal(u) = checkcol(u) - checkrow(u); display checkbal; shows this: ---- 42 PARAMETER checkbal AGRI 0.004, MANU -0.010, SERV -...
by Renger
2 weeks ago
Forum: Tools
Topic: Interfacing GAMS and MATLAB
Replies: 1
Views: 551

Re: Interfacing GAMS and MATLAB

Hi Monireh
Could you attach the code, so I could test it on my computer?
Cheers
Renger
by Renger
2 weeks ago
Forum: Modeling
Topic: Speed up the gams execution
Replies: 2
Views: 1122

Re: Speed up the gams execution

Hi You could try to use the techniques of Tom Rutherford for decomposing the model into a detailed household part and an economic model with one aggregated household. He used this technique to do an analysis for Russia with 55'000 households as described in Rutherford, Tarr, and Shepotylo (2008) htt...
by Renger
2 weeks ago
Forum: Solvers
Topic: Various Answers
Replies: 4
Views: 157

Re: Various Answers

Hi
Your question is posed in a such a general way, that it is hard to give an answer.
What kind of model (where is the code), what is meant by "different"?
Cheers
Renger
by Renger
2 weeks ago
Forum: Modeling
Topic: Conditional statement
Replies: 1
Views: 56

Re: Conditional statement

Hi
It would be helpful if you post the code that causes the errors. This would make it easier to point to the errors you are making.
Cheers
Renger