#5856: [with patch, needs review] elliptic curves over Z/pZ are treated totally
differently than elliptic curves over GF(p)
---------------------------+------------------------------------------------
Reporter: was | Owner: AlexGhitza
Type: enhancement | Status: assigned
Priority: major | Milestone: sage-3.4.2
Component: number theory | Keywords: elliptic curve integers mod prime
---------------------------+------------------------------------------------
Comment(by cremona):
I was expecting that here,
{{{
sage: F = Zmod(101)
92 sage: EllipticCurve(F, [2, 3])
93 Elliptic Curve defined by y^2 = x^3 + 2*x + 3 over
Ring of integers modulo 101
94 sage: E = EllipticCurve([F(2), F(3)])
95 sage: type(E)
96 <class
'sage.schemes.elliptic_curves.ell_finite_field.EllipticCurve_finite_field'>
}}}
both would end up as EllipticCurve_finite_field objects, but I guess that
we have to have a way of constructing the other things, so that is ok.
But would it not be better to change the base_ring (and base_field) of E
in the second case to GF(101)?
Next (but not this patch's fault at all):
{{{
sage: R = Zmod(101)
sage: is_Field(R)
True
sage: is_FiniteField(R)
False
}}}
Now the second is justified since the is_*() functions are supposed to do
a type test, not prove a theorem, but then why should the first not also
return False? Should this be a new ticket?
Here:
{{{
227 raise ValueError, "sequence of coefficients must
have length at 2 or 5"
246 raise ValueError, "sequence of coefficients must
have length between 2 and 5"
}}}
It is [2,5] and not [2..5], and the only valid lengths are 2 and 5, so can
we put that back to how it was?
Sorry to be such a pain with my reviews...I'll give it a positive review
if the very last point is seen to.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/5856#comment:5>
Sage <http://sagemath.org/>
Sage - Open Source Mathematical Software: Building the Car Instead of
Reinventing the Wheel
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
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-trac?hl=en
-~----------~----~----~----~------~----~------~--~---
