Opened 10 years ago
Closed 10 years ago
#10840 closed defect (fixed)
bug in saturation for elliptic curves over Q
Reported by: | cremona | Owned by: | cremona |
---|---|---|---|
Priority: | major | Milestone: | sage-4.7 |
Component: | elliptic curves | Keywords: | saturation eclib |
Cc: | was | Merged in: | sage-4.7.alpha5 |
Authors: | John Cremona | Reviewers: | Gagan Sekhon |
Report Upstream: | Workaround found; Bug reported upstream. | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
Randall Rathbun reports that this crashed badly:
E = EllipticCurve([0,0,0,-13711473216,0]) P = E([-19992,16313472]) Q = E([-24108,-17791704]) R = E([-97104,-20391840]) S = E([-113288,-9969344]) E.saturation([P,Q,R,S]) terminate called after throwing an instance of 'std::bad_alloc' what(): std::bad_alloc --------------------------------------------------------------------------- RuntimeError
I have diagnosed this as coming from a "shortcoming" in eclib's saturation function when dealing with a non-minimal model. (The curve in the example is non-minimal at 2.)
Of course the best solution is for me to patch eclib (see #10903); but in the meantime the simplest solution is to patch Sage to make sure the eclib's satuation is not called with non-minimal models.
A patch is forthcoming!
Attachments (1)
Change History (5)
Changed 10 years ago by
comment:1 Changed 10 years ago by
- Status changed from new to needs_review
comment:2 Changed 10 years ago by
- Description modified (diff)
comment:3 Changed 10 years ago by
- Reviewers set to Gagan Sekhon
- Status changed from needs_review to positive_review
All tests passed, Documentation looks good and code also works.
comment:4 Changed 10 years ago by
- Merged in set to sage-4.7.alpha5
- Resolution set to fixed
- Status changed from positive_review to closed
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applies to 4.6.2.alpha3