I only just spotted this sub-thread since the whole thread concerns
many different things.

I will look into that code since it is doing what is already
implemented twice in Sage-contributed code written by me:  in mwrank
and in my gp scripts.

John

On 18/11/2007, David Harvey <[EMAIL PROTECTED]> wrote:
>
>
> On Nov 18, 2007, at 4:16 AM, Robert Bradshaw wrote:
>
> >> #1130
> >
> > This seems to rely on an earlier patch. (#1120?) See comments on trac.
>
> I'm very concerned about this patch. It is not the case that the LCM
> of the orders of all elements of E(GF(q)) will equal the order of E(GF
> (q)). I haven't tried the code, but if I understand the code
> correctly, it will go into an infinite loop on such cases, and it may
> well give incorrect results in other cases.
>
> For example:
>
> sage: K.<a> = GF(5^3)
> sage: K.polynomial()
> a^3 + 3*a + 3
> sage: E = EllipticCurve([3*a^2 + 2, 2*a + 4])
> sage: E
> Elliptic Curve defined by y^2  = x^3 + (3*a^2+2)*x + (2*a+4) over
> Finite Field in a of size 5^3
> sage: LCM([P.order() for P in E.points()])
> 32
> sage: len(E.points())
> 128
>
> david
>
>
> >
>


-- 
John Cremona

--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to [email protected]
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/
-~----------~----~----~----~------~----~------~--~---

Reply via email to