On Mon, Feb 13, 2012 at 09:14:17AM +0100, Christian Stump wrote: > for your attantion. http://arxiv.org/pdf/1201.5566v1.pdf > > If someone has the time to look into it: please, please report!
I did not know Meinolf was doing that. I guess that he did it as an exercise to learn Python. There are 2 aspects to it. -A new algorithm to compute Kazhdan-Luztig cells recursively, using parabolic subgroups, which is apparently several orders of magnitude more efficient that previous algorithms: very interesting! -A naive (in the sense of straightforward) port of the needed parts of (a rather old version of) Chevie to plain Python. I do not know if much of it is easily usable for a Sage port. By the way, I have a question: what is a Sage port? I ask this because it is my plan to eventually work in Sage (when GAP3 becomes too obsolete). But I must confess that I have not yet started on this plan since I want to finish some large projects on Chevie and I think it is not yet time for me to discard GAP3. I understand that there are several levels of porting: - The first is that Chevie can be used in Sage through the interface to GAP3, thanks to Saliola. -Next, one could map each Chevie type of object to an appropriate Sage class or category; since the design in Sage could be quite different this could be non trivial. Since I have not yet learned properly Sage this is the hardest for me, and is where I am stuck. -One could then write the high-level code of Chevie in Sage, calling GAP3 or GAP4 for the low-level stuff. -Or one could port all the code of Chevie in Sage. This requires in particular efficient cyclotomic numbers (mostly done, if I understand) and efficient permutations (anything done there?). This second question begs the question wether one would also port much of the permutation group library of GAP3/4 to Sage. Even if I do not do it myself, I would be happy to help anyone trying to do any of the above. Best regards, ------------------------------------------------------------------------ Jean MICHEL, Equipe des groupes finis, Institut de Mathematiques UMR7586 Bureau 9D17 tel.(33)157279144, 175, rue du Chevaleret 75013 Paris -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To post to this group, send email to sage-combinat-devel@googlegroups.com. To unsubscribe from this group, send email to sage-combinat-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en.
