Opened 5 weeks ago
Last modified 4 weeks ago
#27479 needs_review defect
Univariate PolynomialRing with 'negdegrevlex' order does not get 'ds' order in Singular
Reported by: | rburing | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-8.8 |
Component: | interfaces | Keywords: | PolynomialRing, Singular, order |
Cc: | Merged in: | ||
Authors: | Ricardo Buring | Reviewers: | |
Report Upstream: | N/A | Work issues: | |
Branch: | u/rburing/MPolynomialRing_libsingular_univariate_allow_other_monomial_orderings (Commits) | Commit: | ef6964686b4e5f703817d3a82d01aa26c4f50280 |
Dependencies: | Stopgaps: |
Description (last modified by )
Using _singular_init_()
univariate polynomial rings get global monomial ordering lp
no matter what:
sage: R.<x> = PolynomialRing(QQ, 1, order='negdegrevlex') sage: R._singular_init_() polynomial ring, over a field, global ordering // coefficients: QQ // number of vars : 1 // block 1 : ordering lp // : names x // block 2 : ordering C
Contrast with multivariate:
sage: S.<y,z> = PolynomialRing(QQ, 2, order='negdegrevlex') sage: S._singular_init_() polynomial ring, over a field, local ordering // coefficients: QQ // number of vars : 2 // block 1 : ordering ds // : names y z // block 2 : ordering C
As long as neg*
orders are allowed (see #10708) this should be fixed (and it seems easy to fix).
This is also the cause of a bug in multiplicity()
for subschemes of the affine line:
sage: A1.<x> = AffineSpace(QQ,1) sage: X = A1.subscheme([x^1789+x]) sage: Q = X([0]) sage: X.multiplicity(Q) 1789
as reported in Ask SageMath question #45777.
Change History (5)
comment:1 Changed 5 weeks ago by
- Description modified (diff)
comment:2 Changed 5 weeks ago by
- Description modified (diff)
comment:3 Changed 5 weeks ago by
- Branch set to u/rburing/MPolynomialRing_libsingular_univariate_allow_other_monomial_orderings
comment:4 Changed 5 weeks ago by
- Commit set to ef6964686b4e5f703817d3a82d01aa26c4f50280
- Status changed from new to needs_review
comment:5 Changed 4 weeks ago by
- Milestone changed from sage-8.7 to sage-8.8
Ticket retargeted after milestone closed (if you don't believe this ticket is appropriate for the Sage 8.8 release please retarget manually)
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New commits:
Trac #27479: Allow monomial ordering != 'lp' for univariate MPolynomialRing_libsingular