On 9/30/07, Mike Hansen <[EMAIL PROTECTED]> wrote: > > > There is something *extremely* fishy about the base ring here! It's > > a *multivariate* polynomial ring: > > Here is the culprit: > > sage: type(PolynomialRing(ZZ, 1, 'x')) > <class > 'sage.rings.polynomial.multi_polynomial_ring.MPolynomialRing_polydict_domain'> > > while > > sage: type(PolynomialRing(ZZ, 'x')) > <class 'sage.rings.polynomial.polynomial_ring.PolynomialRing_integral_domain'> > > I've created a ticket: http://www.sagetrac.org/sage_trac/ticket/764 > and will post a patch later on.
Wait! This would an explicit intentional design choice, not a bug. I think it should be possible to create ZZ['x'] but as a multivariate polynomial ring instead of a univariate polynomial ring, since there are certain things one can do with multivariate polynomial rings that don't make sense with single variate rings. Maybe I'm wrong, since things have been so well developed by now. I would like some further discussion and input (esp. from Martin Albrecht) on this before changing anything. > > sage: s = hlqp5_m.change_ring(ZZ['x']) > > sage: time w=s^(-1) > > CPU times: user 0.10 s, sys: 0.00 s, total: 0.10 s > > > > Even 8 works pretty quickly: > > > > sage: hlqp8 = [ symmetrica.hall_littlewood(p) for p in Partitions(8) ] > > sage: hlqp8_m = matrix([[ x.coefficient(p) for p in Partitions(8) ] > > for x in hlqp8]) > > sage: s = hlqp8_m.change_ring(ZZ['x']); s > > 22 x 22 dense matrix over Univariate Polynomial Ring in x over Integer Ring > > sage: time w=s^(-1) > > CPU times: user 2.13 s, sys: 0.04 s, total: 2.17 s > > Wall time: 2.29 > > sage: time t=s*s > > CPU times: user 0.24 s, sys: 0.00 s, total: 0.24 s > > Those numbers seem much better. > > --Mike > > > > -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://sage.scipy.org/sage/ and http://modular.math.washington.edu/sage/ -~----------~----~----~----~------~----~------~--~---
