From nowozin at gmail.com Wed Jun 25 11:13:21 2008 From: nowozin at gmail.com (Sebastian Nowozin) Date: Wed, 25 Jun 2008 17:13:21 +0200 Subject: [CHiPPS] Blis and branch-and-price Message-ID: <48626091.2010401@gmail.com> Dear Alps/Bcps/Blis developers, I downloaded, compiled and played around with Blis trunk today and I am seriously impressed. Everything behaves as expected, the parallel mode with mpich2 works, and the output looks as beautiful as it does with Cplex ;-) However, I wonder if branch-and-price is possible using Blis. I though if it is, the BlisModel class must contain the necessary methods but while it contains a lot of methods to handle cuts, there are no methods to create variables in the branch and bound tree. Is this true or do I miss something obvious? Also, in case branch-and-price is possible, is there an example or a particular source file I can get some further information as to how setup the problem? Thanks, Sebastian From Yan.Xu at sas.com Wed Jun 25 11:35:46 2008 From: Yan.Xu at sas.com (Yan Xu) Date: Wed, 25 Jun 2008 11:35:46 -0400 Subject: [CHiPPS] Blis and branch-and-price In-Reply-To: <48626091.2010401@gmail.com> References: <48626091.2010401@gmail.com> Message-ID: Hi Sebastian, I am glad that you like the framework. Blis doesn't support branch and price yet. It is in our plan, but haven't implement it due to time limit. Contribution is always welcome. Best, Yan -----Original Message----- From: chipps-bounces at list.coin-or.org [mailto:chipps-bounces at list.coin-or.org] On Behalf Of Sebastian Nowozin Sent: Wednesday, June 25, 2008 11:13 AM To: CHiPPS at list.coin-or.org Subject: [CHiPPS] Blis and branch-and-price Dear Alps/Bcps/Blis developers, I downloaded, compiled and played around with Blis trunk today and I am seriously impressed. Everything behaves as expected, the parallel mode with mpich2 works, and the output looks as beautiful as it does with Cplex ;-) However, I wonder if branch-and-price is possible using Blis. I though if it is, the BlisModel class must contain the necessary methods but while it contains a lot of methods to handle cuts, there are no methods to create variables in the branch and bound tree. Is this true or do I miss something obvious? Also, in case branch-and-price is possible, is there an example or a particular source file I can get some further information as to how setup the problem? Thanks, Sebastian _______________________________________________ CHiPPS mailing list CHiPPS at list.coin-or.org http://list.coin-or.org/mailman/listinfo/chipps From ted at lehigh.edu Wed Jun 25 14:42:20 2008 From: ted at lehigh.edu (Ted Ralphs) Date: Wed, 25 Jun 2008 14:42:20 -0400 Subject: [CHiPPS] Blis and branch-and-price In-Reply-To: <48626091.2010401@gmail.com> References: <48626091.2010401@gmail.com> Message-ID: <4862918C.2020605@lehigh.edu> As Yan already noted, column generation is not yet supported in BLIS, but there's a project under development called DECOMP that also plugs into CHiPPS and will provide support for column generation, as well as a number of other decomposition-based bounding methods for integer programming. It is not on COIN yet, but I could probably provide a copy if you want to check it out. Hopefully, it will be in COIN within the next few months. Cheers, Ted Sebastian Nowozin wrote: > Dear Alps/Bcps/Blis developers, > > I downloaded, compiled and played around with Blis trunk today and I am > seriously impressed. Everything behaves as expected, the parallel mode > with mpich2 works, and the output looks as beautiful as it does with > Cplex ;-) > > However, I wonder if branch-and-price is possible using Blis. I > though if it is, the BlisModel class must contain the necessary methods > but while it contains a lot of methods to handle cuts, there are no > methods to create variables in the branch and bound tree. Is this true > or do I miss something obvious? > > Also, in case branch-and-price is possible, is there an example or a > particular source file I can get some further information as to how > setup the problem? > > Thanks, > Sebastian > _______________________________________________ > CHiPPS mailing list > CHiPPS at list.coin-or.org > http://list.coin-or.org/mailman/listinfo/chipps -- Dr. Ted Ralphs Associate Professor Industrial and Systems Engineering Lehigh University (610)758-4784 ted 'at' lehigh 'dot' edu coral.ie.lehigh.edu/~ted