# Ticket #6583: trac_6583-fix.patch

File trac_6583-fix.patch, 1.5 KB (added by rlm, 13 years ago)
• ## sage/schemes/elliptic_curves/descent_two_isogeny.pyx

```# HG changeset patch
# User Robert Miller <rlm@rlmiller.org>
# Date 1256871612 25200
# Node ID 696eaa305a4a5d7e77bb4d069bc8e9536f40d879
# Parent  34d613efca2325d5a719ce5b37cd6070c23d229e
Fixes for #6583

diff -r 34d613efca23 -r 696eaa305a4a sage/schemes/elliptic_curves/descent_two_isogeny.pyx```
 a EXAMPLE:: sage: from sage.schemes.elliptic_curves.descent import test_valuation as tv sage: from sage.schemes.elliptic_curves.descent_two_isogeny import test_valuation as tv sage: for i in [1..20]: ...    print '%10s'%factor(i), tv(i,2), tv(i,3), tv(i,5) 1 0 0 0 sage: n1, n2, n1_prime, n2_prime = two_descent_by_two_isogeny(E) sage: log(n1,2) + log(n1_prime,2) - 2 # the rank 1 sage: E = EllipticCurve('1088j1') sage: x,y = var('x,y') sage: E = EllipticCurve(y^2 == x^3 + x^2 - 25*x + 39) sage: n1, n2, n1_prime, n2_prime = two_descent_by_two_isogeny(E) sage: log(n1,2) + log(n1_prime,2) - 2 # the rank 2 sage: E = EllipticCurve('59450i') sage: E = EllipticCurve(y^2 + x*y + y == x^3 - 131*x + 558) sage: n1, n2, n1_prime, n2_prime = two_descent_by_two_isogeny(E) sage: log(n1,2) + log(n1_prime,2) - 2 # the rank 3