The function generic order_from_multple() does allow the information to be cached, and the function Victor referred to should use that.
John 2009/7/31 VictorMiller <victorsmil...@gmail.com>: > > Simon, Thanks. I think that in order for this to work, that finite > field should have a new method, something like > > @cached_method > _cofactor_information(self): > N = self.order() > return [ (N//p**r,p) for p,r in arith.factor(N)] > > which would factor the order, and then return all the cofactors and > prime associated with them, and then change multiplicative order to > use that method. > > Victor > > On Jul 31, 11:16 am, Simon King <simon.k...@nuigalway.ie> wrote: >> Hi Victor, >> >> On Jul 31, 3:59 pm, VictorMiller <victorsmil...@gmail.com> wrote: >> >> > I was just looking at the code for multiplicative_order in >> > finite_field_element.py, and noticed that it factors the group order, >> > and find the "cofactors" corresponding to each prime power dividing >> > the order (which is really the only algorithm that I know to do >> > this). To avoid repeating this calculation for elements of finite >> > fields it would be nice if the finite field could cache this >> > information, so that it wouldn't have to be recalculated. The same >> > remark should hold for finite abelian groups (since it's really the >> > same algorithm). >> >> Do you know the cached_method decorator? In order to cache the field >> (or group) order, you just need to import the decorator by >> from sage.misc.cachefunc import cached_method >> and then, right in front of the method definition, put @cached_method: >> >> @cached_method >> def multiplicative_order(FiniteField_givaroElement self): >> ... >> >> 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 URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
