Oh thanks a bunch! I feel the book will be *incredibly* helpful; and yep I'll submit the pull request :)
Alex On Mar 18, 9:16 am, Alan Bromborsky <abro...@verizon.net> wrote: > On 03/18/2012 12:09 AM, Aaron Meurer wrote: > > > > > > > > > I wouldn't trust much from that section anyway, though, since the > > paper is from 1998. > > > Aaron Meurer > > > On Sat, Mar 17, 2012 at 10:07 PM, Aaron Meurer<asmeu...@gmail.com> wrote: > >> Is that a preprint? Some of the sections seem unfinished (for > >> example, section 10). > > >> Aaron Meurer > > >> On Sat, Mar 17, 2012 at 8:27 PM, Alan Bromborsky<abro...@verizon.net> > >> wrote: > >>> On 03/17/2012 04:59 PM, Aaron Meurer wrote: > >>>> On Sat, Mar 17, 2012 at 2:45 PM, Aleksandar Makelov > >>>> <amake...@college.harvard.edu> wrote: > >>>>>> I think a main reference is "Permutation Group Algorithms" by Akos > >>>>>> Seress - Cambridge Tracts in Mathemathics 152 published 2003. > >>>>> Thanks! The "Handbook of computational group theory" also looks like > >>>>> serious business. Unfortunately, neither of these is a free resource; > >>>>> I might end up buying one, I don't know. > > >>>>>> I worked as a student last year and may apply as mentor this year. > >>>>>> Please take a look at my branches in github. I was implementing the > >>>>>> Schreier Sims algorithm but I ran out of time unfortunately. You could > >>>>>> either help me merge my branches in or take off where I left. > >>>>> OK, I'll hopefully have the time to take a look this coming week. > > >>>>>> Is this necessary? All groups are isomorphic to the permutation group > >>>>>> anyway. Groups for specific structures can make use of functionality > >>>>>> implemented for them (matrix group -> sympy matrices, galois -> > >>>>>> polys) > >>>>>> for basic operations and can implement the mapping to the perm group > >>>>>> module for group theoretic operations. > >>>>> So I looked at the permutations module and it has a lot of nice group- > >>>>> ish functions (like composing/inverting permutations, raising to > >>>>> powers, conjugating permutations, getting the order (as an element of > >>>>> the corresponding symmetric group) of a permutation, ...). These can > >>>>> be incorporated in a representation of groups using permutation > >>>>> groups; Galois groups would fit perfectly in this representation since > >>>>> they naturally live inside the symmetric groups, and yes a lot of the > >>>>> functions in the polys module will be helpful. > > >>>>> Also, there are generators for common groups like S_n, C_n, D_n, A_n > >>>>> in the context of permutation representations. All this provides a > >>>>> nice foundation for defining a Group class or something like that, > >>>>> with one of the ways of representing it being the permutation > >>>>> representation. Other ways (e.g., matrices, character tables, list of > >>>>> generators and relations) could probably be added later, and > >>>>> functionality to go from one to representation to another? > > >>>>> In other news, I found a bug inside the generators.py file in the > >>>>> permutations module - the dihedral group D_2 of order 4 is given a > >>>>> wrong permutation representation. I have a fix for this (well it's > >>>>> quite straightforward, just manually considering the case n=2 and > >>>>> outputting the right representation, because the general algorithm > >>>>> fails there), what should I do about it? > >>>> Submit a pull request! This can be your patch for the patch requirement. > > >>>> Aaron Meurer > > >>>>> Aleksandar Makelov > > >>>>> -- > >>>>> 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. > > >>> See attached! > > >>> -- > >>> 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. > > Link to download of - Handbook of Computational Group Theory > > http://www.4shared.com/office/LtxPTggL/Handbook_of_Computational_Grou... > > Attached is another way of implementing Lie groups > > Lie groups as spin groups - Doran, Hestenes, Sommen, Van Acker - 1993.pdf > 299KViewDownload -- 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.
