#4901: bug in elliptic logarithm
---------------------------+------------------------------------------------
Reporter: cremona | Owner: was
Type: defect | Status: new
Priority: major | Milestone: sage-3.4
Component: number theory | Keywords: elliptic logarithm
---------------------------+------------------------------------------------
#4214 introduced something which causes this example to fail:
{{{
sage: EllipticCurve("4390c2").gens()[0].elliptic_logarithm()
---------------------------------------------------------------------------
MemoryError Traceback (most recent call
last)
/home/john/sage-3.2.2.rc1/devel/sage-elllog/<ipython console> in
<module>()
/home/john/sage-3.2.2.rc1/local/lib/python2.5/site-
packages/sage/schemes/elliptic_curves/ell_point.py in
elliptic_logarithm(self, embedding, precision, algorithm)
1211 E_pari = ER.pari_curve(prec=precision)
1212 pt_pari = [pari(emb(self[0])), pari(emb(self[1]))]
-> 1213 log_pari = E_pari.ellpointtoz(pt_pari,
precision=precision)
1214 while prec_words_to_bits(log_pari.precision()) <
precision:
1215 working_prec = 2*precision
/home/john/sage-3.2.2.rc1/local/lib/python2.5/site-
packages/sage/libs/pari/gen.so in sage.libs.pari.gen._pari_trap
(sage/libs/pari/gen.c:38603)()
/home/john/sage-3.2.2.rc1/local/lib/python2.5/site-
packages/sage/libs/pari/gen.so in
sage.libs.pari.gen.PariInstance.allocatemem (sage/libs/pari/gen.c:34732)()
/home/john/sage-3.2.2.rc1/local/lib/python2.5/site-
packages/sage/libs/pari/gen.so in sage.libs.pari.gen.init_stack
(sage/libs/pari/gen.c:37647)()
MemoryError: Unable to allocate 4096000000 bytes memory for PARI.
}}}
caused by an infinite loop.
The problem has been diagnosed by me and Alex and I'll post a patch
shortly.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4901>
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
-~----------~----~----~----~------~----~------~--~---
