On Tue, Jan 7, 2014 at 1:58 AM, Nathann Cohen <nathann.co...@gmail.com>wrote:
> > Something is indeed wrong, and I have experienced similar problems in > the past. What version of CPLEX and which version of Sage are you using? I > am using IBM ILOG CPLEX 12.5.1.0, and Sage 5.12 on Fedora Linux 19 and Sage > 5.10 on Fedora 13. > > HMmmmm... Well, to be honest I don't know. The truth is : I don't remember > having met a nasty bug like that with Sage at any point, though it is > possible that it may have been fixed since since you do not use the latest > version of Sage.. Coud you try it with a more recent version of Sage, like > the 6.0 ? > I upgraded to Sage 6.0, and the output is still wrong. I then checked IBM, and a new version of CPLEX was released in early December 2013. With CPLEX 12.6.0 and Sage 6.0, I now get the correct answers. So it seems that CPLEX 12.5.10 was the culprit. Though it is surprising to me that there would be such a basic bug. I am somewhat worried that there is something wrong with the CPLEX interface code in Sage, but it seems very straightforward. I recall having weird problems using CPLEX in Sage in the past; one specific instance from summer 2012 jumps to mind. I'll see if I can't dig up one of those instances and see if they have been fixed with new versions of Sage and CPLEX. > Actually, there is a trac ticket waiting for review related to how LP > solvers handle bounds, but I do not think it is related to this bug > http://trac.sagemath.org/ticket/15622 > (it does *not only* fix GLPK code) > Do you mean http://trac.sagemath.org/ticket/14581 ? Best wishes, Stephen -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/groups/opt_out.
