Hi all I am trying to do computations with symmetric functions over different alphabets.
This seems to have been part of the SFA package, itself part of the mu- EC package, itself considered a deprecated part of the MuPAD-combinat package... (see http://mupad-combinat.sourceforge.net/doc/en/index/referenceManual.html ). Is it still in Sage via this chain? Sage currently has a roundabout way to do this, but it's not so pretty, requires all kinds of coercions and is probably slower than it needs to be: sA = SFASchur(QQ) sB = SFASchur(sA) x = sum(sB(1/i)*sB(sA([i]))*sB([i]) for i in (1..5)) pA = SFAPower(QQ) pB = SFAPower(pA) pB(x) Is there any better way to do this? In addition, I really want to do my computations in a power series ring over the commutative ring of (Schur, whatever) symmetric functions in 2 alphabets. The extra variable t would let me keep track of the weight of the degrees of the polynomials involved, since for each term of my computation the degrees are the same in the two alphabets. So I tried something like this: T.<t> = PowerSeriesRing(sB,default_prec=5) but Sage (4.1.combinat and 4.1.1 on the server) complains: TypeError: base_ring must be a commutative ring Is there a way to circumvent that? Any help greatly appreciated! Thank you Paul PS: It might also be good to edit http://wiki.sagemath.org/combinat/Installation since this is a natural place you end up at when you want to install combinat, and it s confusing with that title... --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
