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 <[email protected]> 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 <[email protected]> wrote: >> On 03/17/2012 04:59 PM, Aaron Meurer wrote: >>> >>> On Sat, Mar 17, 2012 at 2:45 PM, Aleksandar Makelov >>> <[email protected]> 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 [email protected]. >>>> To unsubscribe from this group, send email to >>>> [email protected]. >>>> 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 [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
