Opened 10 years ago
Closed 9 years ago
#6296 closed defect (fixed)
linbox minpoly over small finite fields is TOTALLY BROKEN
Reported by: | was | Owned by: | was |
---|---|---|---|
Priority: | critical | Milestone: | sage-4.3.3 |
Component: | linear algebra | Keywords: | |
Cc: | Merged in: | sage-4.3.3.alpha0 | |
Authors: | William Stein | Reviewers: | Yann Laigle-Chapuy |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
On Wed, Jun 10, 2009 at 6:03 PM, Yann<yannlaiglechapuy@gmail.com> wrote: > > ---------------------------------------------------------------------- > | Sage Version 4.0.1, Release Date: 2009-06-06 | > | Type notebook() for the GUI, and license() for information. | > ---------------------------------------------------------------------- sage: A=matrix(GF(3),2,[0,0,1,2]) sage: R.<x>=GF(3)[] sage: D={ x:0 , x+1:0 , x^2+x:0 } sage: for i in range(10000): D[A._minpoly_linbox()]+=1 sage: D {x: 38266, x + 1: 29397, x^2 + x: 32337} > You're absolutely right! This *sucks* -- it seems like nothing we have ever wrapped in Linbox is right at first. Hopefully the issue is that somehow the algorithm is only supposed to be probabilistic, and we're just misusing it in sage (quite possible).
Attachments (2)
Change History (8)
comment:1 Changed 10 years ago by
comment:2 Changed 9 years ago by
- Description modified (diff)
- Report Upstream set to N/A
Changed 9 years ago by
comment:3 follow-up: ↓ 4 Changed 9 years ago by
- Description modified (diff)
- Status changed from new to needs_review
comment:4 in reply to: ↑ 3 Changed 9 years ago by
We should at least take the lcm of the results so far:
line 974: g = g.lcm(self._minpoly_linbox(var)
otherwise, it seems ok.
Yann
comment:5 Changed 9 years ago by
- Status changed from needs_review to positive_review
Ok positive review.
As an aside, is their any reason the result is cached but never fetched?
Yann
comment:6 Changed 9 years ago by
- Merged in set to sage-4.3.3.alpha0
- Resolution set to fixed
- Reviewers set to Yann Laigle-Chapuy
- Status changed from positive_review to closed
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from a linbox devel:
My remarks