Hi Jean-Pierre, On Thu, 9 Sep 2010 02:13:27 -0700 (PDT) Jean-Pierre Flori <jpfl...@gmail.com> wrote:
> I created a Ticket on Sage's Trac: > http://trac.sagemath.org/sage_trac/ticket/9880 > > It could be a problem with the comparison function > "expair_rest_is_less" used by "std::sort" function like in the > following link: > http://gcc.gnu.org/ml/gcc-bugs/2010-08/msg01163.html This is indeed the problem. Thanks for tracking it down. In the process of adapting GiNaC for use in Sage, I changed the comparison functions to give a consistent order between different runs. Apparently, the new comparison functions I wrote are not consistent. For a long time, I wanted to rip out these new functions, and use them only for printing. The following patch is a first step towards this: http://sage.math.washington.edu/home/burcin/pynac/pynac_order.patch After applying this patch to pynac (see here [1] for instructions on how to set up a pynac development environment), the segfault you reported, and the bug at #9046 goes away. Note that this is very much a work in progress. I didn't take care to make sure these comparison functions are consistent either. In the process of copying things over, I even flipped a few signs in the results. This needs much work to be finished, we need to make sure the order is consistent and correct, and it matches the one currently used by Sage. The issue of accessing the operands of a symbolic expression also needs to be sorted out, but that's merely a user interface issue. I'd appreciate help with any of this, since I don't have much time to spend on Sage/pynac these days. I'd be glad to answer any questions though. Cheers, Burcin -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
