Nicolas M. Thiery wrote: > Some words of advice, if I may. Please follow as closely as possible > the design and conventions used for NCSF. It is far from perfect, but > the overall organization results from experience accumulated over many > years. Yes, the rationale for each design choice should eventually be > documented within Sage; for the moment, there are already quite a few > things in the MuPAD-Combinat handbook (available on MuPAD-Combinat's > web site. Strongly enforcing consistency among all our (Hopf) algebras > with several bases (Sym, QSym, NCSF, Pol, ...) will make it easier to > spot whatever can be factored out. It will also help newcomers see and > understand the overall logic and mimic it for their own examples.
I definitely agree with this--it means one less thing that I will have to think about :) > If you notice parts which feel clumsy (you will!), or have suggestions > for improvements, please take good notes of them. But don't implement > them right away, or only in a separate experiment. Instead, we should > discuss them and update systematically all the algebras according to > the outcome of the discussion. I'll admit that I have only sat down once to really think about this since Sage days. (Since classes start today, it will be at least a few weeks before I get to do this again.) But I will say what I got stuck on--that was the technical details of using Singular rings when we can. In other words the 'usual' basis for multivariate polynomials in n variables is indexed by compositions of length n, with (a1, a2, ..., an) corresponding to x1^a1 ... xn^an. This should be relatively straightforward to implement in a slow way, but I think we want to take advantage of Singular. That is, multiplication should convert to Sage's polynomial ring, multiply there, and then convert back. I can't remember the details, but I remember I found this tricky. Anyway, the point is that this is an implementation detail which does not show up in NCSF, so any advice from the master (Nicolas) will be appreciated, I'm sure, even if it is Adrien and not I who ends up using it. Dear Adrien, I'm sorry I may not be able to do much with this in the immediate future. But if you do work on this, please let me know your progress. (For example, please send me off-list emails when you push anything to the sage-combinat server). I will try to offer as much help as I can. Best, Jason --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
