Infeasibilities in CPLEX

GAMS
1

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

2

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/videos/conflict-refiner-feasopt-cplex-dealing-model-infeasibility/

Perhaps this helps.

-Michael

3

Thanks very much for your help!

Luca