On Nov 1, 2007, at 12:11 AM, William Stein wrote: > On Thu, 01 Nov 2007 00:00:57 -0700, Robert Bradshaw > <[EMAIL PROTECTED]> wrote: >> The answer is, I believe, yes. Should it rely on the check flag to >> decide whether or not to try and factor? > > Wait, is there a good reason to ever compute the discriminant in > order to > represent elements of the field? > > Generally, check is supposed to be for checking whether > the polynomial is irreducible or not, which for a quadratic > field Q(sqrt(D)) just means checkin whether D is a perfect > square, which is a lot easier than factoring D.
Smaller D will result in faster arithmetic, but it's probably not worth factoring (might be worth doing trial division for squares of small primes though). - Robert --~--~---------~--~----~------------~-------~--~----~ 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/ -~----------~----~----~----~------~----~------~--~---
