Re: Question on elliptic curve group orders...

[wraithx@morpheus.net]

On 1/22/2017 2:17 PM, Bill Allombert wrote:
> On Sun, Jan 22, 2017 at 02:03:29PM -0600, wraithx@morpheus.net wrote:
> > Hello all,
> >
> > I have some code that should work in Sage, but I don't have that installed.
> > I do have pari/gp installed.  Can someone help me convert the following code
> > so that I can run it in pari/gp?
>
> FindGroupOrder(p,s)=
> {
>      K = Mod(1,p);
>      v = K*(4*s);
>      u = K*(s^2-5);
>      x = u^3;
>      b = 4*x*v;
>      a = (v-u)^3*(3*u+v);
>      A = a/b-2;
>      x = x/v^3;
>      b = x^3 + A*x^2 + x;
>      E = ellinit([0,b*A,0,b^2,0],K);
>      factor(ellcard(E))
> }
>
> the others are similar except for
> x,y = P.xy()
> which is
> [x,y] = P;
>
> Cheers,
> Bill.

That worked perfectly!  Thanks for your help.

-David C.