Hi, My first thought is that it is a slow convergency process. It often occurs when linear constraints are involved with particular coefficients. A first clue may be the number of propagations done in one call to Space::status(). For the cases where the search ends (with a big amount of time) you may check the number of propagations done. If it is abnormally huge, it's probably a slow convergence. Without digging in the model and trace the search, I can't say much more. Sorry ....
Regards, Vincent 2015-04-15 16:05 GMT+02:00 Christian Schulte <[email protected]>: > Hi, > > > > This could be a feature and not a bug in that constraint propagation is > just very slow to converge. For floating point numbers there is this risk. > > > > I would not know what to suggest without knowing how the model looks like > but I am also not an expert in floating point. Vincent: do you have an idea? > > > > Cheers > > Christian > > > > -- > > Christian Schulte, www.gecode.org/~schulte > > Professor of Computer Science, KTH, [email protected] > > Expert Researcher, SICS, [email protected] > > > > *From:* [email protected] [mailto:[email protected]] *On > Behalf Of *Kurt Van Den Branden > *Sent:* Wednesday, April 15, 2015 4:00 PM > *To:* [email protected] > *Subject:* [gecode-users] model with float variables sometimes hangs > during search > > > > hi, > > I have a Gecode model that uses float variables. > I use a BAB searchengine with a Search::TimeStop object to interrupt the > search when it takes too long. > > I noticed that when the model is created with certain parameters, the > search isn't interrupted at the requested timelimit. > it either continues a lot longer than allowed, or it doesn't stop at all. > > in these cases, the debugger shows that it's the method Space::status that > doesn't return sometimes. > it keeps on propagating and never stops. > > I haven't been able to reproduce this with a limited test model yet. > > Does anybody have tips on what could cause this problem? > > Kind Regards, > > *Kurt Van Den Branden | Agfa Graphics* > -- Vincent Barichard Université d'Angers (LERIA) Tel: 02 41 73 52 06 Département Informatique Fax: 02 41 73 50 73 H203
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