#11960: bug in matrix of frobenius when p = 3
-----------------------------+----------------------------------------------
Reporter: jen | Owner: was
Type: defect | Status: new
Priority: major | Milestone: sage-4.7.3
Component: number theory | Keywords:
Work_issues: | Upstream: N/A
Reviewer: | Author:
Merged: | Dependencies:
-----------------------------+----------------------------------------------
The code for computing the matrix of frobenius when p = 3 does not seem to
be implemented:
{{{
sage: E = EllipticCurve('83a1')
sage: EW = E.short_weierstrass_model()
sage: EW.is_ordinary(3)
True
sage: EW.matrix_of_frobenius(3)
---------------------------------------------------------------------------
NotImplementedError Traceback (most recent call
last)
/home/jen/<ipython console> in <module>()
/home/jen/sage/sage-4.7.1/local/lib/python2.6/site-
packages/sage/schemes/elliptic_curves/padics.pyc
in matrix_of_frobenius(self, p, prec, check, check_hypotheses,
algorithm)
1521 # todo: implement the p == 3 case
1522 if p < 5:
-> 1523 raise NotImplementedError, "p (=%s) must be at least 5" %
p
1524
1525 prec = int(prec)
NotImplementedError: p (=3) must be at least 5
}}}
However, telling Sage that you're dealing with a hyperelliptic curve calls
other code, which seems to run into problems when p = 3:
{{{
sage: EW
Elliptic Curve defined by y^2 = x^3 + 1269*x - 10746 over Rational Field
sage: R.<x> = QQ['x']
sage: C= HyperellipticCurve(x^3 + 1269*x - 10746)
sage: C.matrix_of_frobenius(3)
[ 3^-109 +
2*3^-104 + 3^-102 + 2*3^-101 + 2*3^-100 + 3^-99 + 3^-97 + 3^-92 +
O(3^-89) 2*3^-101 + 3^-99 + 2*3^-97 + 3^-96 + 2*3^-95 + 2*3^-94 +
3^-91 + 3^-90 + 2*3^-87 + 2*3^-86 + 2*3^-85 + 3^-84 + 3^-83 + 2*3^-82
+ O(3^-81)]
[ 3^-110 + 2*3^-109 + 2*3^-107 + 2*3^-106 + 3^-102 + 2*3^-101 +
3^-100 + 3^-99 + 3^-98 + 3^-97 + 3^-94 + 2*3^-93 + 2*3^-92 + O(3^-90)
2*3^-102 + 3^-101 + 2*3^-96 + 3^-94 +
2*3^-92 + 3^-91 + 2*3^-89 + 2*3^-88 + 3^-86 + 3^-84 + 3^-83 +
O(3^-82)]
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11960>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
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.
