Hi Martin! On 1 Dez., 19:02, Martin Albrecht <m...@informatik.uni-bremen.de> wrote: > Hi there, > > the following code is really, really really (REALLY!) slow:
Well, the default implementation creates a polynomial ring with 10000 variables in the background when you say x[10000], and another ring with 10001 variables if you then say x[10001]. My original motivation for the InfinitePolynomialRings was the computation of Symmetric Gröbner Bases. But from a couple of recent posts I learn that people use it for different applications. And for these applications, the sparse implementation might be better. So, perhaps one should change the default? Anyway, it is not slow at all when doing it sparsely: sage: IP = InfinitePolynomialRing(QQ,implementation='sparse') sage: x = IP.gen() sage: x10000 = x[10000] sage: %time 1/2*x10000 CPU times: user 0.00 s, sys: 0.02 s, total: 0.02 s Wall time: 0.04 s 1/2*x10000 sage: timeit('y=1/2*x10000') 625 loops, best of 3: 133 µs per loop Here, you just have one variable in the background: sage: x10000.polynomial().parent() Univariate Polynomial Ring in x10000 over Rational Field So, who votes for changing the default? Cheers, Simon -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org