Opened 9 years ago
Closed 3 years ago
#12129 closed defect (wontfix)
MPolynomial_libsingular.is_squarefree fails with linear factors
Reported by: | culler | Owned by: | AlexGhitza |
---|---|---|---|
Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
Component: | algebra | Keywords: | square free |
Cc: | jakobkroeker | Merged in: | |
Authors: | Paul Zimmermann, John Cremona | Reviewers: | Travis Scrimshaw |
Report Upstream: | N/A | Work issues: | |
Branch: | u/cremona/12129 (Commits, GitHub, GitLab) | Commit: | 17fdcc12d73b82446e8122cb3e0de3fbcb1671ba |
Dependencies: | Stopgaps: | todo |
Description
sage: x, y = QQ['x','y'].gens() sage: f = x*y sage: f.is_squarefree() False sage: f = (x+y)*(x+3) sage: f.is_squarefree() False
This may be related to an inconsistency in the Singular sqrfree function, which sometimes includes a unit in the square free factorization, but other times does not.
Change History (17)
comment:1 Changed 9 years ago by
comment:2 Changed 8 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:3 Changed 7 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:4 Changed 7 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:5 Changed 7 years ago by
- Milestone changed from sage-6.3 to sage-6.4
comment:6 Changed 6 years ago by
- Cc jakobkroeker added
comment:7 Changed 6 years ago by
- Stopgaps set to todo
comment:8 Changed 3 years ago by
This can surely be closed as the examples posted are now computed correctly. Same as at #12198.
comment:9 Changed 3 years ago by
- Milestone changed from sage-6.4 to sage-duplicate/invalid/wontfix
- Reviewers set to Travis Scrimshaw
- Status changed from new to needs_review
comment:10 Changed 3 years ago by
- Status changed from needs_review to positive_review
comment:11 Changed 3 years ago by
shouldn't we include a non-regression test?
comment:12 Changed 3 years ago by
I am not opposed. Feel free to use this ticket for that.
comment:13 Changed 3 years ago by
here is a corresponding patch:
--- a/src/sage/rings/polynomial/multi_polynomial_libsingular.pyx +++ b/src/sage/rings/polynomial/multi_polynomial_libsingular.pyx @@ -4734,6 +4734,18 @@ cdef class MPolynomial_libsingular(MPolynomial): sage: h = f^2 sage: h.is_squarefree() False + + TESTS:: + +Check if :trac:`12129` is fixed:: + + sage: x, y = QQ['x','y'].gens() + sage: f = x*y + sage: f.is_squarefree() + True + sage: f = (x+y)*(x+3) + sage: f.is_squarefree() + True """ # TODO: Use Singular (4.x) intrinsics. (Temporary solution from #17254.) return all([ e == 1 for (f, e) in self.factor() ])
comment:14 Changed 3 years ago by
I agree that tests should be added, both here and at #12198, but was a little too lazy to do it myself.
comment:15 Changed 3 years ago by
- Branch set to u/cremona/12129
- Commit set to 17fdcc12d73b82446e8122cb3e0de3fbcb1671ba
- Status changed from positive_review to needs_review
Travis could you re-review this? I thought that this doctest would do for both tickets. Thanks.
New commits:
17fdcc1 | #12129: add doctest to show issue has been fixed
|
comment:16 Changed 3 years ago by
- Status changed from needs_review to positive_review
I was also a little too lazy to do it as well. ^^;;
Thanks Paul and John.
comment:17 Changed 3 years ago by
- Resolution set to wontfix
- Status changed from positive_review to closed
see also #12198 and #12404. Maybe some of those tickets can be removed as duplicate.
Paul