Ticket #13615: trac_13615_3rd_review.patch

File trac_13615_3rd_review.patch, 2.0 KB (added by defeo, 6 years ago)
  • sage/schemes/elliptic_curves/isogeny_small_degree.py

    # HG changeset patch
    # User Luca De Feo <luca.defeo@polytechnique.edu>
    # Date 1378304508 -7200
    #      Wed Sep 04 16:21:48 2013 +0200
    # Node ID 0b390ff2270e6d36df01162aa5731bccc5fa38bf
    # Parent  20d27842cad4ea702544bdaa12d826102a6791e0
    Spelling errors and simplified a case in isogenies_sporadic_Q
    
    diff --git a/sage/schemes/elliptic_curves/isogeny_small_degree.py b/sage/schemes/elliptic_curves/isogeny_small_degree.py
    a b  
    339339# 2, 3, 5, 7 or 13. In these cases l is equal to 11, 17, 19, 37, 43,
    340340# 67 or 163. We refer to these l as "sporadic".
    341341#
    342 # For each possible sporadic (l,j) pair, _spradic_Q_data return
     342# For each possible sporadic (l,j) pair, _sporadic_Q_data returns
    343343# ([a4,a6],f) where [a4,a6] are the invariants of a short Weierstrass
    344344# model of one curve with that j-invariant,and f is the factor of
    345345# degree (l-1)/2 of the l-division polynomial of that curve defining
     
    575575        isog.set_pre_isomorphism(E_to_Ew)
    576576        return [isog]
    577577    if l is None:
    578         if j in [-32768, -121, -24729001]:
    579             return isogenies_sporadic_Q(E, Integer(11))
    580         if j in [QQ(-297756989)/2, QQ(-882216989)/131072]:
    581             return isogenies_sporadic_Q(E, Integer(17))
    582         if j==-884736:
    583             return isogenies_sporadic_Q(E, Integer(19))
    584         if j in [-9317, -162677523113838677]:
    585             return isogenies_sporadic_Q(E, Integer(37))
    586         if j==-884736000:
    587             return isogenies_sporadic_Q(E, Integer(43))
    588         if j==-147197952000:
    589             return isogenies_sporadic_Q(E, Integer(67))
    590         if j==QQ(-262537412640768000):
    591             return isogenies_sporadic_Q(E, Integer(163))
    592         else:
    593             return []
     578        return sum(filter(None, [isogenies_sporadic_Q(E, Integer(l))
     579                                 for l in (11, 17, 19, 37, 43, 67, 163)]),
     580                   [])
    594581
    595582def isogenies_2(E):
    596583    """