I don't seem able to edit my previous message to add this information, but the GiNaC team seems to have picked up the bug report and patched it: http://www.cebix.net/pipermail/ginac-devel/2010-March/001724.html
On Mar 24, 4:19 pm, G B <g.c.b.at.w...@gmail.com> wrote: > Thanks Burcin. I'm having problems getting sage to download the > source properly through my corporate firewall. I've submitted the bug > report to the GiNaC dev list. > > On Mar 23, 2:06 am, Burcin Erocal <bur...@erocal.org> wrote: > > > > > Hi Greg, > > > On Mon, 22 Mar 2010 15:47:54 -0700 (PDT) > > > G B <g.c.b.at.w...@gmail.com> wrote: > > > Burcin-- > > > > Now that I've managed to divide the discussion between two groups, I > > > should try to help organize the mess I made. > > > > Ondrej mentioned in the sage-support discussion that he's opened > > > ticket 8564. Unfortunately I don't understand the plumbing well > > > enough to know if 8564 and 8565 are addressing the same or different > > > problems. As you mention, Sage seems to import atan2 from GiNaC. > > > 8564 looks to be improving the import of the functionality from Sympy. > > > They are unrelated issues. > > > > From a user perspective, it would be best if the default flavor worked > > > without needing to learn the unique syntax of a sub-package, but > > > beggars can't be choosers. =) > > > Yep, we really need to fix the atan2 in Sage. > > > > I'm happy to try and help if given some guidance. I'm a reasonably > > > capable programmer, but I'm completely unfamiliar with Sage and a > > > touch intimidated by the complexity of it. > > > I can help with the first steps. Although the fix doesn't seem so > > obvious to me (I don't have time to start debugging properly), it should > > still be a good project to start with. > > > The code for evaluating atan2 lives in the c++ library pynac [1], which > > is based on GiNaC. > > > [1]http://pynac.sagemath.org/ > > > There are two approaches to fix this problem, > > > - one can either look into the "automatic evaluation" [2, 3] function > > of atan2 in GiNaC [4], > > > [2]http://www.ginac.de/tutorial/Symbolic-functions.html > > [3]http://www.ginac.de/tutorial/Automatic-evaluation.html > > [4]http://pynac.sagemath.org/hg/file/9ff767fb0c18/ginac/inifcns_trans.cp... > > > You can also just report the problem to the GiNaC developers by > > writing to the ginac-list mailing list: > > >http://www.ginac.de/Lists.html > > > - or override the automatic evaluation function with a python function > > (I implemented this recently in pynac.) by defining an _eval_() > > method in the class sage.functions.trig.Function_arctan2. > > > If you choose to fix the c++ code here is a short guide to get started > > with pynac development: > > >http://wiki.sagemath.org/pynac/start > > > Feel free to ask more questions. Especially the symbolics subsystem and > > the pynac interface really needs documentation. I find that answering > > questions is way easier than writing manuals. > > > Thank you. > > > Burcin -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org To unsubscribe from this group, send email to sage-devel+unsubscribegooglegroups.com or reply to this email with the words "REMOVE ME" as the subject.
