[Cbc] How to debug infeasible problems

[David Ibarra Gómez]

I do not know an automatic way of doing that. 
I usually build a second problem (to be solved if the original its infeasible) full of slacks on each constraint with very high cost on the objective function. The non-zero slacks gives clues of which is the problem. 
Some times I run several problems changing the cost of the slacks if there are too much non zero.

I know it's not exactly what you looked at, but it has work for me on real problems. User found very useful to have a clue about what's wrong when the problem it's infeaseble and they are changing input data.
Kind regards.
David Ibarra 



> To: cbc at list.coin-or.org
> From: christopher.gross at unikat.uni-augsburg.de
> Date: Mon, 30 May 2016 15:47:56 +0200
> Subject: [Cbc] How to debug infeasible problems
> 
> Hi,
> 
> I am using CBC in a software that generates models based on user input. 
> Sometimes, users input invalid data leading to an infeasible model. As 
> the amount of data they enter is not very small, it is often hard to see 
> at a glance which data exactly causes the problem.
> 
> Is it possible to configure CBC to output why a problem is infeasible? 
> It would be great if it could give the line name where the conflict 
> occurs, similar to what CPLEX does. I had a look around the config 
> options, but could not find how to turn this on. Am I missing something 
> or is this feature not available?
> 
> Thanks and regards,
> 
> Christopher
> -- 
> Christopher Gross, M.Sc.
> 
> Lehrstuhl für Health Care Operations/Health Information Management
> 
> Universitäres Zentrum für Gesundheitswissenschaften am Klinikum Augsburg
> (UNIKA-T), Neusässer Straße 47, 86156 Augsburg;
> 
> Wirtschaftswissenschaftliche Fakultät, Universität Augsburg,
> Universitätsstraße 16, 86159 Augsburg
> 
> 
> Tel.: +49 821 598-6454
> 
> E-Mail:  christopher.gross at unikat.uni-augsburg.de
> Web:  http://www.wiwi.uni-augsburg.de/bwl/brunner/
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