Hmm, In looking at ell_point.py at line 1181 it looks like it does the right thing. Somehow the pari error of division by 0 (perhaps in non- prime finite fields?) doesn't get raised as a ZeroDivisionError. This is a problem with the interface with pari:
p = 100019 K.<a> = GF(p) L.<b> = GF(p^2) K(1)/K(0) L(1)/L(0) Note that the errors given by K and L and different. And, if we work over small characteristic, say p=7, we get a different set of errors. Victor On Aug 6, 1:13 pm, VictorMiller <victorsmil...@gmail.com> wrote: > Slight change. The code I gave works, but the following fails. I > really don't know what there is about a non-prime finite field that > causes this. > > Victor > > p=100019 > E = EllipticCurve(j=GF(p^2,'r')(1728)) > M = (p+1)//3 > # find an element of order 3 > while True: > P = M*E.random_element() > if P != 0: > break > P.weil_pairing(2*P,3) > > On Aug 6, 1:05 pm, VictorMiller <victorsmil...@gmail.com> wrote: > > > In calculating the Weil Pairing of two points I get a pari division by > > zero error. Needless to say this shouldn't happen. I think that the > > solution is that if either of the miller_functions that are calculated > > yield a 0 then the value of the Weil Pairing must be 1. > > > Here's some code that provokes the error > > > p=100019 > > E = EllipticCurve(j=GF(p)(1728)) > > M = (p+1)//3 > > # find an element of order 3 > > while True: > > P = M*E.random_element() > > if P != 0: > > break > > P.weil_pairing(2*P,3) > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
