#11936: image_type of galois_representation of EllipticCurve hangs on first call
-------------------------------+--------------------------------------------
Reporter: dkrenn | Owner: cremona
Type: defect | Status: new
Priority: minor | Milestone: sage-4.7.3
Component: elliptic curves | Keywords: ellipitc curve,
galois_representation, image_type, kash
Work_issues: | Upstream: N/A
Reviewer: | Author:
Merged: | Dependencies:
-------------------------------+--------------------------------------------
Comment(by dkrenn):
{{{
sage: set_verbose(2)
sage:
EllipticCurve([1,-1,0,-107,-379]).galois_representation().image_type(7)
verbose 1 (1331: free_module.py, coordinate_module) rational in-place
Gauss elimination on 0 x 0 matrix
verbose 1 (1331: free_module.py, coordinate_module) done with gauss
echelon form (time = 0.0)
verbose 1 (1331: free_module.py, coordinate_module) rational in-place
Gauss elimination on 0 x 0 matrix
verbose 1 (1331: free_module.py, coordinate_module) done with gauss
echelon form (time = 0.0)
verbose 1 (805: gal_reps.py, image_type) the image cannot be non-split,
found u=1 (time = -0.031877)
verbose 1 (225: gal_reps.py, _division_field) trying to build the
extension by adjoining the 7-torsion poitns (time = 0.076129)
verbose 1 (170: gal_reps.py, _splitting_field) polynomial changed to X^24
- 42*X^23 - 230251*X^22 - 69533303*X^21 - 8922533774*X^20 +
347214199528*X^19 + 286338627568224*X^18 + 41629615315907472*X^17 +
3108220855196029216*X^16 + 122316792051635948928*X^15 -
4520750190750939811456*X^14 - 1804229340708484633384448*X^13 -
224151265240179594471852544*X^12 - 15517866240175312371054405632*X^11 -
573518329951131274679784851456*X^10 - 5793224956125895412494849712128*X^9
+ 228526103828692771157402376626176*X^8 -
14135660323094856284334906260815872*X^7 -
2416289128770519856029858966252322816*X^6 -
131374567677496568053592598343642185728*X^5 -
4111917752635666789463237955234875572224*X^4 -
81967433407110205420237005816145633083392*X^3 -
1040145626904817944512274612355466016587776*X^2 -
7776955374441598739723910668195770718486528*X -
26550411922404424048904353608400249053773824 (time = -0.91587)
verbose 1 (170: gal_reps.py, _splitting_field) degree of the field is now
6 (time = 0.100131)
verbose 1 (170: gal_reps.py, _splitting_field) degree of the field is now
18 (time = 0.348146)
verbose 1 (225: gal_reps.py, _division_field) the y-coordinate need to be
adjoined, too (time = 3.732357)
verbose 1 (805: gal_reps.py, image_type) field of degree 36. try to
compute galois group (time = 4.676417)
}}}
Using `trace`, it turns out that it hangs at the following position:
{{{
> /usr/opt/Sage-4.7.1-amd64/local/lib/python2.6/site-
packages/sage/schemes/elliptic_curves/gal_reps.py(1159)image_type()
1158 try:
-> 1159 G = K.galois_group()
1160 except:
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11936#comment:2>
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.
