On 10/26/07, David Harvey <[EMAIL PROTECTED]> wrote: > sage: N = 5^1000 > sage: R = Integers(N) > sage: S.<x> = PolynomialRing(R) > sage: v = R(37) > sage: f = S([v]) > > Am I correct in saying that with the current codebase, the last line > in the above code is converting v to a ZZ_pX via a decimal string?
Instead do this so the problem is more pronounced: sage: N = 5^100000 sage: R = Integers(N) sage: S.<x> = PolynomialRing(R) sage: v = R(7^100000) sage: time f = S([v]) I then tracked down the problem which is in the ntl_ZZ_pContext function in ntl_ZZ_pContext.pyx, where the context is cached. Unfortunately, the frickin' context is cached as a decimal *string*, so every single cached access to the context is extremely expensive -- for more expensive than not even bothing to cache the context would be. The patch that will soon appear here: http://trac.sagemath.org/sage_trac/ticket/1009 will fix things so that the cache uses the hash of the context, which I implemented (along with hash's of ntl_ZZ's). Exactly the same mistake is made in ntl_GF2EContext.pyx, which the above patch also fixes, hopefully. -- William --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
