#12509: computation of height of point on elliptic curve over Q(sqrt(5)) is
WRONG
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Reporter: was | Owner: was
Type: defect | Status: new
Priority: critical | Milestone: sage-5.0
Component: number theory | Keywords:
Work_issues: | Upstream: N/A
Reviewer: | Author:
Merged: | Dependencies:
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Comment(by nbruin):
A little `hg blame sage/schemes/elliptic_curves/ell_point.py` and `hg
history sage/schemes/elliptic_curves/ell_point.py` shows that this code
comes from #8496 , merged in sage-4.4.alpha1. The next change to this file
happened with #8827 in a later release. I have verified that the example
in the ticket gives the same result on sage-4.4, so the error has been
there all along.
Note that:
{{{
sage: [P.height(precision=p) for p in [53..70]]
[1.35648516097058, 1.37988660372465, 1.392904136135677,
1.388358180620918, 1.390651822960756, 1.3901262440498197,
1.3886249896939375, 1.3887137996432686, 1.38889123047486600,
1.38868605331097548, 1.38879145662338488, 1.38876788728230994,
1.388772046900726933, 1.388778979290526601, 1.388773433409450769,
1.3887772462291215145, 1.3887758164353761832, 1.3887774411997285045]
}}}
so the computation is probably not really wrong. It's probably just a
matter of precision estimates being off.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/12509#comment:2>
Sage <http://www.sagemath.org>
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