GAMS World Forum

Please don't include your model in the message body: attach the .gms file instead.

Also, if you want feedback about the error, attach the .lst file and the log output from your run. The command line option lo=2 or lo=4 is useful for getting your log output in a file.

-Steve

Douglas, Your first question is basically, "Why do I have to match variables and equations in MCP?" Essentially, the bounds you set on the variables and the matching you choose between variables and equations influences the set of solutions for the MCP model. If you choose one matching, yo...

Andrew C, It would be helpful to attach your GAMS source: don't include it in the text. Also, attach the complete .lst and .log files. And if you feel the source is too big to attach, then create a copy and cut, cut, cut until you have a small reproducible example. Probably you will find the solutio...

Nia, Basis information is stored not only in GAMS variables but also in GAMS equations. For example, if you resolve the same model, it uses 0 iterations. Here's some code to do that: Solve ex1 using LP maximizing z; file log /''/; put log; putclose ' ' / 'Iterations: ', ex1.iterusd / ' ' /; Solve ex...

Kamal,

You'll probably get a better response if you start a new thread instead of using an unrelated thread from a year ago.

-Steve

jch, This happens occasionally and can be very frustrating. Sometimes the feasibility of a model can depend on tolerances: if CPLEX uses looser tolerances, that might lead to feasibility. Another issue is scaling. If you have very large numbers in your model (variable levels, coefficients, RHS) it c...

Grace,

If you include the .log file from the run you'd make it easier to help you.

I can only guess now: perhaps you are not using the most recent GAMS version. The Jump output from convert is a fairly new feature.

-Steve

Paulo, We don't use strict inequalities in optimization. Google strict inequality math programming for a wealth of reasons why, perspectives, examples, etc. You could use a Big-M method: given a binary variable y, use x-y <= M * y y-x <= M * (1-y) if M is large enough, the constraint x-y<=0 is on wh...

Rodrigue, If I understand correctly, you have a set of activities a1*a43, and these activities belong to one of the following 4 types: agr, ind, ser, sad. You want to make this assignment and use it. This is a very standard thing to do. You should use a multi-dimensional set as described here: https...

Hello, Many of the compilation errors that occur have to do with syntax - e.g. using symbols that are not declared, declaring an EEEQUATION, etc. But during compilation GAMS also checks for logical errors that would occur during the execution of the GAMS source. That's was error 352 is: an indicatio...