#17254: Upgrade to Singular-4-0-2
-------------------------------------+-------------------------------------
Reporter: jdemeyer | Owner:
Type: enhancement | Status: new
Priority: major | Milestone: sage-7.3
Component: packages: | Resolution:
standard | Merged in:
Keywords: | Reviewers:
Authors: Jakob Kroeker, | Work issues:
Jean-Pierre Flori, Jeroen Demeyer | Commit:
Report Upstream: N/A | 9ec51342d57b7b66aa576edca3b1810768f3a593
Branch: | Stopgaps:
u/tscrim/upgrade_singular-17254 |
Dependencies: |
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Comment (by klee):
Replying to [comment:196 jakobkroeker]:
> Question: is the behaviour described in the documentation of the
'degree' function in sage
> {{{
> Note that a matrix term ordering alters the grading of the generators
> of the ring; see the tests below. To avoid this behavior, use
either
> ``exponents()`` for the exponents themselves, or the optional
> argument ``std_grading=False``.
> }}}
>
> natural and is it what a user would expect? Then we could(?) fix it
using a different appropriate call:
> {{{
> sage: sage: tord = TermOrder(matrix([3,0,1,1,1,0,1,0,0]))
> sage: sage: R.<x,y,z> = PolynomialRing(QQ,'x',3,order=tord)
> sage: sage: (x^3*y+x*z^4).degree() # 9
> ('p_Totaldegree', 4)
> ('p_WTotaldegree', 9)
> ('p_WDegree', 9)
> ('pFDeg', 4)
> ('pLDeg', 5)
> }}}
As the person who introduced the matrix term ordering into Sage, I think
that it was just due to the Singular behavior that a matrix term ordering
changes the grading of the generators according to the first row of the
matrix in Sage. It shocked everyone including John, and was regarded as a
bug. So if we can make the grading and the matrix term ordering
independent, switching to Singular 4, then I would be happy. Of course it
should go with an appropriate deprecation warning.
--
Ticket URL: <http://trac.sagemath.org/ticket/17254#comment:199>
Sage <http://www.sagemath.org>
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