I am using GAMS for solving a MILP problem which includes binary variables. However there is a problem in the solution. Surprisingly, I have seen that one of the binary variables in the solution has a found value of "-1" another one "2". That is not acceptable. I do not know what happened. GAMS gives me the message primal infeasible.
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Can you show me the code? – Dinesh.hmn Jan 23 '17 at 22:41
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here is the link https://www.researchgate.net/post/What_is_primal_infeasible_solution_in_GAMS?_tpcectx=profile_questions – iman Jan 24 '17 at 07:53
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GAMS gives me this code:"resolved with fixed discrete variables".something is wrong in GAMS because it is not logical case. – iman Jan 24 '17 at 08:49
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First, if GAMS reports the problem as infeasible, you should not rely on the variable levels. Better check the solver & model status first and look at the variables only, if these status codes do not indicate a problem. Then: What version of GAMS did you actually use? I just tried your model with the recent version (24.8.2) and that solved it without any problems, and also with all binary variables either 0 or 1. – Lutz Jan 24 '17 at 10:28
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so,Lutz do u mean my model does not have problem,right?,actually I solved it without any problem before,however since yesterday I faced this problem,is it probability to overload gams has difficultis? – iman Jan 24 '17 at 10:42
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Right, running it with a recent version I do not see any problem with your model. Therefore I was wondering if you are using the same GAMS version I used, or if you used an old one. If the latter is the case, you might be OK after switching to the new one. – Lutz Jan 24 '17 at 11:08