ConflictRefiner() returns a different upper bound than the one saved in the model

Question

My model status is integer infeasible. I used ConflictRefiner() to check which constraints are mutually contradictory.

Then I use display_conflicts to check which constraints are "at fault".

This is the output:

I found this weird since my ub is set to 15. I checked the code and everything looks good and I also inspected the model values and as you can see for variable 107, ub=15.

I can't really understand why this would happen. Thank you in advance for your help!

How did you set the variable upper bound, at construction time, or later by setting the `ub` property? — Philippe Couronne, Nov 23 '20 at 08:25

score 0 · Answer 1 · answered Nov 23 '20 at 10:55

0

I confirm this is a bug with DOcplex's conflict refiner; it does not take into account variable bounds set by properties. There are two workarounds:

either define bounds what variable creation time.
or start a solve() even with a small time limit(e.g. 1s) before launching the conflict refiner.

This bug will be fixed in the next release of DOcplex. Thanks for reporting this.

answered Nov 23 '20 at 10:55

Philippe Couronne

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This bug is fixed in DOcplex 2.18, which was released today. Let me know if this fixes your problem. – Philippe Couronne Nov 23 '20 at 16:02

ConflictRefiner() returns a different upper bound than the one saved in the model

1 Answers1