[Cbc] Nauty / Symmetry detection support

[Tiago Maduro Dias]

Please find an example problem attached. It’s meant to be a k longest cyclic path problem.

Thanks in advance!

Tiago Maduro Dias.

On 28 Oct 2018, 15:01 -0100, John Forrest <john.forrest at fastercoin.com>, wrote:
> Nauty is to some extent a "WIP".  I would be glad if someone were to improve it.
>
> I have fixed compile problem in trunk.  I have also added an -orbit simple option, which just adds symmetry breaking constraints.
>
> If you wish to send me a problem, I can look to see what nauty or other options can do to improve situation.
>
> John Forrest
>
>
>
> On 27/10/2018 23:01, Tiago Maduro Dias wrote:
> > Hi,
> >
> > I’m dealing with a problem that has quite a few symmetries but I’m finding that adding restrictions to reduce or eliminate them has a significant impact on CBC’s execution time.
> >
> > I was wondering if there were alternative and possibly more efficient approaches, such as using Nauty.
> >
> > After some time fiddling, I’m coming to the conclusion that Nauty support in CBC is currently broken, e.g., there’s a reference to rootModels[i]->zapSymmetry() in Cbc/src/CbcModel.cpp but I see no declaration for it anywhere in the code.
> >
> > This made me wonder if Nauty is supposed to work with the trunk version of CBC or if it's just an abandoned WIP? If the former, can someone give me some pointers about what I should be doing to get it to compile?
> >
> > Best regards,
> >
> > Tiago Maduro Dias.
> >
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