#19276: precision problem computing heights on elliptic curves
-------------------------+-------------------------------------------------
Reporter: | Owner:
cremona | Status: needs_review
Type: | Milestone: sage-6.9
defect | Resolution:
Priority: major | Merged in:
Component: | Reviewers:
elliptic curves | Work issues:
Keywords: | Commit:
height precision | 3ea3fc73d85a9b50fb618f63c345bce415cf7e1a
Authors: John | Stopgaps:
Cremona |
Report Upstream: N/A |
Branch: |
u/cremona/19276 |
Dependencies: |
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Comment (by cremona):
I am not exactly sure what general fix would work for this sort of
situation:
{{{
sage: K.<a> = NumberField(x^2-x-104)
sage: E = EllipticCurve([1, a - 1, 1, -816765673272*a - 7931030674178,
1478955604013312315*a + 14361086227143654561])
sage: D = E.discriminant()
sage: [v(D) for v in K.embeddings(RealField())]
[0.000000000000000, -9.70868378243995e40]
sage: [v(D) for v in K.embeddings(RealField(100))]
[0.00000000000000000000000000000, -9.7086837824399448843367001731e40]
sage: [v(D) for v in K.embeddings(RealField(200))]
[0.00000000000000000000000000000000000000000000000000000000000,
-9.7086837824399448843367001730524854139792000000000000000000e40]
sage: [v(D) for v in K.embeddings(RealField(300))]
[-4.32015718504110363878523822853740762057165316169725154810335814374378729622544830930841973e-35,
-9.70868378243994488433670017305248541397919999999999999999999999999999999999567984281495890e40]
}}}
if the users asks for the image of a field element in some embedding?
Where the field element is non-zero but the image appears to be zero?
What did you have in mind?
--
Ticket URL: <http://trac.sagemath.org/ticket/19276#comment:7>
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