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Infeasibilities in CPLEX

Posted: Mon Nov 05, 2018 9:57 am
by Luca
Dear all,

I am programming in GAMS using CPLEX as MIP solver. I activated the following options for CPLEX

feasopt 1
numericalemphasis 1
scaind 1

CPLEX should provide the "less infeasible" solution to the problem. However I obtain the following error:

Feasible solution.
----------------------------------------------------------
Cplex reported an infeasible model, but no infeasibilities
larger than the feasibility tolerance: 0.01
could be found.
----------------------------------------------------------

Thanks in advance for all your help.
Best regards,
Luca

Re: Infeasibilities in CPLEX

Posted: Tue Nov 06, 2018 8:19 am
by bussieck
Some models are on the edge of feasiblity/infeasibility. Often this goes together with poor scaling. The IBM Cplex folks have a video about dealing with infeasibility in general but also a section about these special models: https://developer.ibm.com/docloud/blog/ ... asibility/

Perhaps this helps.

-Michael

Re: Infeasibilities in CPLEX

Posted: Tue Nov 06, 2018 1:15 pm
by Luca
Thanks very much for your help!

Luca