On Thursday, 7 June 2012 13:50:59 UTC+2, Volker Braun wrote: > > Is cbraid really the best/fastest implementation of braid groups out > there? How does it compare to what GAP can do?
Indeed, there is (nonstandard) GAP package "braid", packaged in gap_packages spkg, and as far as I am told by one of its authors, Sergey Shpectorov, their package mapclass http://web.mat.bham.ac.uk/S.Shpectorov/mapclass/ can do all of what "braid" can, and more. Just from glancing at it, the author doesn't use many C++ features. Not > necessarily a minus. It implements bubble sort, really? Also seems to be > very hard to maintain, many nested loops with undocumented one-letter > variables. > > > > On Thursday, June 7, 2012 12:28:08 PM UTC+1, mmarco wrote: >> >> I have been working on an implementation of braid groups for sage >> (together with free and finitely presented groups). So far i have a >> preliminary version (see ticket #12339). It is still not feature >> complete and also very slow compared to cbraid[1], for example, but >> it >> is usable. >> >> In order to speed it up, i want to interface cbraid directly. But i >> have no experience at all with c++ or python interfaces to external >> libraries. Please can someone help me with it? For example, i would >> need to write a function that takes an integer n and a list of >> integers l (that represents a braid of n strands), and uses cbraid >> to >> compute the left normal form. I have tried to do it directly with >> ctypes, but i only got error messages. >> >> Thanks in advance. >> >> [1]http://code.google.com/p/cbraid/ > > -- 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
