Opened 12 months ago

Last modified 5 weeks ago

#29832 new defect

apparently wrong monomial order in ToricIdeal?

Reported by: dimpase Owned by:
Priority: major Milestone: sage-9.4
Component: algebraic geometry Keywords:
Cc: vbraun Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

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Description

It seems that neglex used there isn't the right order, for it's not even a Groebner basis order. See

https://ask.sagemath.org/question/51851/toric-ideal-of-point-configuration-yielding-whole-ring/

for details and an example showing a meaningless answer from Sage. Namely the following is wrong:

sage: A = matrix([[1,0,0,0,-1,-1,-2],[0,1,0,-1,-1,-2,-3]])
....: IA = ToricIdeal(A); IA
....: 
Ideal (1) of Multivariate Polynomial Ring in z0, z1, z2, z3, z4, z5, z6 over Rational Field

IMHO it should be something like degrevlex instead. Or, indeed, Signular provides weighted orders that can be used.

Change History (2)

comment:1 Changed 8 months ago by mkoeppe

  • Milestone changed from sage-9.2 to sage-9.3

comment:2 Changed 5 weeks ago by mkoeppe

  • Milestone changed from sage-9.3 to sage-9.4

Moving to 9.4, as 9.3 has been released.

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