[Cbc] [CBC] gomory makes problem infeasible (even in version 2.9.5)

[mg]

Sorry, here's the missing attachment

Regards,
Marco

2015-07-28 15:36 GMT+02:00 John Forrest <john.forrest at fastercoin.com>:

> Attached????????????
>
>
> On 24/07/15 08:29, mg wrote:
>
> Hi All,
> if I remember correctly in version 2.9.4, gomory cuts generator started to
> give some problems causing false infeasibilities. In theory, version 2.9.5
> contains some fixes for this issue, but I think it's not completely
> corrected since I've found a model that appears infeasible unless you
> disable gomory cuts.
>
> Attached you can find the LP file. Please note that I'm running this model
> through callCbc(), and you need to disable heuristics otherwise
> DiveCoefficient will find a solution before gomory cuts "too much"..
>
> Here's a piece of code to reproduce the problem :
>
> OsiClpSolverInterface solver;
> CbcModel model(solver);
> model.solver()->readLp("infeas.lp");
> std::string args("-heur off -solve"); // using "-gomory off -solve" it
> works
> callCbc(args, model);
>
> Thanks in advance,
> Marco
>
>
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