Search found 1042 matches
- 10 months ago
- Forum: Modeling
- Topic: Assistance with conditional non-equals
- Replies: 4
- Views: 2046
Re: Assistance with conditional non-equals
I see. Debugging models is hard. What you need to do is to take be "better" solution you get by just providing the .l (or leave this out because it has no effect) and look at this solution. Explain the solution to yourself and detect the flaws in this solution. Next look at the equation th...
- 10 months ago
- Forum: Syntax
- Topic: Dimension Different Error (electricity pricing model)
- Replies: 2
- Views: 4171
Re: Dimension Different Error (electricity pricing model)
I think you need to upload something that lets us reproduce the error. I can't do this from the code snippets you have pasted.
-Michael
-Michael
- 10 months ago
- Forum: Syntax
- Topic: Loading data from Excel Sheet into GAMS
- Replies: 4
- Views: 5497
Re: Loading data from Excel Sheet into GAMS
Sure, if you provide the Excel files to see what's going on.
-Michael
-Michael
- 10 months ago
- Forum: Modeling
- Topic: Assistance with conditional non-equals
- Replies: 4
- Views: 2046
Re: Assistance with conditional non-equals
I have no idea what you are asking. The attached GAMS model runs though nicely. I don't find any .fx, I only find some .l in your code. They have no effect (since a MIP solver usually ignores the starting point if not instructed otherwise). If I turn the .l into .fx I still get a good solution but w...
- 10 months ago
- Forum: API
- Topic: Trouble installing Python GAMS API on Mac OS
- Replies: 5
- Views: 4864
Re: Trouble installing Python GAMS API on Mac OS
You have a Mac with an M1 or M2 chip but the GAMS 34 distribution is Intel only. So you would need an Intel Python running under Rosetta 2 on you machine. The native M1/M2 port for GAMS was introduced with GAMS 43 (see https://www.gams.com/latest/docs/RN_43.html#g4310_PLATFORMS). So many good reason...
- 10 months ago
- Forum: Syntax
- Topic: ERROR 790 AND 257 IN THE LAST SENTENCE
- Replies: 1
- Views: 3610
Re: ERROR 790 AND 257 IN THE LAST SENTENCE
You don't have a bi-level optimization problem. You have a two-stage stochastic program! The GAMS compiler gives you good help: 171 solve project max z use EMP scenario dict; **** $790,257 **** 257 Solve statement not checked because of previous errors **** 790 Symbol dimension mismatch **** The fol...
- 10 months ago
- Forum: Solvers
- Topic: How to deal with degenerate solutions
- Replies: 4
- Views: 5470
Re: How to deal with degenerate solutions
and it starts reporting solutions, which I've interpreted, rightly or wrongly, as the model finding solutions with the same objective value. This is wrongly assumed. If you would have send the entire width of the log I could have shown you the difference in incumbent values. With what you sent I ca...
- 10 months ago
- Forum: Tools
- Topic: Model status Infeasible when using GUSS
- Replies: 1
- Views: 6071
Re: Model status Infeasible when using GUSS
Not clear what problem you describe. When I run the model you uploaded I get: --- Scenario s0: Records read: 4650 --- Solution statistics for scenario s0 --- Unmatched Records 0 --- Solver Status 1 Normal Completion --- Model Status 1 Optimal --- Objective Value 2.80346e+09 --- Resource Usage 281.79...
- 10 months ago
- Forum: Solvers
- Topic: How to deal with degenerate solutions
- Replies: 4
- Views: 5470
Re: How to deal with degenerate solutions
Hi ,not sure I understand everything what you write here. Degeneracy usually means (see https://glossary.informs.org/second.php?page=D.html#Degeneracy) that we have multiple solution of the same value. You describe that Cplex "always identifies several hundred solutions prior to solving". ...
- 10 months ago
- Forum: Solvers
- Topic: System limits were reached on cluster
- Replies: 7
- Views: 6509
Re: System limits were reached on cluster
UCM_h.log This all looks very much like the cluster is killing your jobs. GAMS runs the solver as an executable (communicating the model instance via scratch files) so even if the solver dies, the GAMS job should nicely continue and write proper lst files. Since this does not happen (and since the ...