> Currently, the ordering of a ring is determined by a string "name":
> TermOrder.__init__(self, name='lex', n = 0, blocks=True)
> respectively "order": PolynomialRing(base_ring, arg1=None, arg2=None,
> sparse=False, order='degrevlex', names=None, name=None,
> implementation=None)
> Of course, it seems natural to define a matrix ordering by passing a
> matrix:
> sage: M = Matrix(2,2, [1,3,1,0])
> sage: R.<x,y> = PolynomialRing(QQ,2,order=M)
>
> But it is perhaps not so nice to break compatibility with the current
> way of defining an ordering by strings.
>
> Closer to Singular syntax would be
> sage: R.<x,y> = PolynomialRing(QQ,2,order='M(1,3,1,0)')
Think this would be rather un-pythonic: converting an object into a string
instead of using it directly.
> But what about block orderings? If one allows a matrix ordering to be
> defined by a matrix, then I guess the blocks should be listed:
> sage: P.<a,b,c,d,e> = PolynomialRing(QQ,5,order=[M,'degrevlex'])
Have you seen this?
sage: TermOrder('deglex',3) + TermOrder('degrevlex',2)
deglex(3),degrevlex(2) term order
> Or, if one goes with strings:
> sage: P.<a,b,c,d,e> = PolynomialRing(QQ,5,order='M(1,3,1,0),degrevlex
> (3)'])
I would like to avoid this string business as much as possible. I find it
rather ugly (that's personal taste of course)
Cheers,
Martin
--
name: Martin Albrecht
_pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99
_otr: 47F43D1A 5D68C36F 468BAEBA 640E8856 D7951CCF
_www: http://www.informatik.uni-bremen.de/~malb
_jab: martinralbre...@jabber.ccc.de
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