Hi Michael, Perhaps I am misunderstanding what you are trying to do. I was thinking you were starting with a polynomial in, say, R.<x,y,z> that you know is symmetric and you want its expression in expressed in terms of elementary symmetric functions. Whereas in that paper, they seem to be computing very specific symmetric polynomials by applying the constraints of the geometry. However, there are some specialized change of bases that could be done, such as p -> e using the contents of section 2, that could be faster (although in that case, Sage seems to be pretty fast). Or have I misunderstood something?
Thanks, Travis On Tuesday, April 21, 2020 at 10:00:35 AM UTC+10, Michael Jung wrote: > > Thanks for your reply Travis. > > Here are different computations compared, which take milliseonds up to > seconds: https://orbilu.uni.lu/bitstream/10993/21949/2/ChernLib.pdf > > In contrast, doing a similar computation with the same polynomials using > `SymmetricFunctions` takes hours. > > However, I think this is a special case they consider, which makes the > computation probably faster. > > Kind regards > Michael > > Am Dienstag, 21. April 2020 01:52:43 UTC+2 schrieb Travis Scrimshaw: >> >> Hi Michael, >> The process is to take a polynomial, convert it to the monomial sym >> func basis, then to the elementary basis (which is outsourced to >> symmetrica). Do you have some references for these efficient algorithms to >> convert a polynomial directly to the elementary basis? >> >> Best, >> Travis >> >> >> On Tuesday, April 21, 2020 at 3:18:37 AM UTC+10, Michael Jung wrote: >>> >>> Dear Sage developers, >>> >>> currently, I am working on an alternative algorithm to compute >>> characteristic forms. I hope to gain a speed-up here. For this reason, I >>> need to express symmetric polynomials in terms of elementary symmetric >>> functions. At the moment, I am playing around with `SymmetricFunctions`. >>> However, the implemented algorithm seems to be very slow. I know that there >>> are quite efficient algorithms out there, but are they accessible in Sage? >>> >>> Thanks for your help and best wishes >>> Michael >>> >> -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-devel/6cea93fc-4697-4e8d-8d7f-3e471eba6b42%40googlegroups.com.
