I wrote this 3 days ago and somehow put it in drafts instead of sending it. Hope it still helps.
On Sat, Mar 24, 2012 at 10:53 PM, Aleksandar Makelov <amake...@college.harvard.edu> wrote: > > > On Mar 24, 10:39 pm, Aaron Meurer <asmeu...@gmail.com> wrote: > >> How could it be too late? >> >> > > Well yeah I hoped it's not :) I was wondering about that because it'd > take a massive amount of changes over different modules to put all > abstract algebraic structures on a common setting -- but I think > that's the right direction to treat this stuff (like, abstract algebra > is abstract so in order to implement it we need more abstractness :) ) > > >> > >> >> Well the GAP people have obviously thought about this problem a lot >> more than we have, and they have quite a bit implemented, so it is a >> good place to look for references. Obviously, we will want to modify >> some things to make them more Pythonic, or to make them fit better >> with other parts of SymPy. For example, GAP is written in C, which is >> not object oriented, so depending on how they implemented their data >> structures, we may want to do it different (not to mention that Python >> has its own independent set of data structures from C with their own >> advantages and disadvantages). >> >> Aaron Meurer >> > > Yep the GAP guys appear to be solid citizens. They have a 900 page > reference and also all the C-code is freely available. Apart from that Sage also has a lot - in python or cython. See for example http://hg.sagemath.org/sage-main/file/c239be1054e0/sage/groups/perm_gps/permgroup.py#l1 However, their license is GPL, not BSD, so you can't use it directly. Hopefully, it is another good reference for you to look at though. You can see from the author field, it seems I wrote (many years ago) a few of those methods. Of course, I am more than happy to relicense any of my code as BSD, in case that helps. > they have tables for a LOT of known finite groups. I think this is > going to help a lot - they are referred to in Chapter 11 of The > Handbook on Computational Group Theory and could speed up some of the > algorithms. > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
