#15061: Pari can't handle all polynomial resultants
-------------------------------------------------+-------------------------
Reporter: robharron | Owner:
Type: defect | Status:
Priority: major | needs_info
Component: algebra | Milestone: sage-6.2
Keywords: pari, resultant, sylvester | Resolution:
matrix | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
-------------------------------------------------+-------------------------
Comment (by pbruin):
Replying to [comment:9 gagern]:
> Replying to [comment:8 pbruin]:
> > There seems to be a different problem here, namely that the class of
that polynomial inherits from `Polynomial_singular_repr`, even though the
base field does not have a conversion to Singular.
>
> `polynomial_element_generic.Polynomial_generic_field` inherits from
`polynomial_singular_interface.Polynomial_singular_repr`. That inheritance
was introduced in
[http://git.sagemath.org/sage.git/commit/?id=35bb3ea22b07ee4477ce70906a4aa7439cdf7bd6
35bb3ea] from 2007.
That commit only changed the order of the superclasses; the inheritance
was there before.
> Unfortunately I can't see what kind of bug this was supposed to fix. It
seems like a bad move to me, though, since that class clearly assumes that
you can convert to singular without further checks.
I agree that it is strange for polynomials over arbitrary fields to
inherit from that class. An alternative would be to "manually" prescribe
this inheritance for polynomials over fields that support conversion to
Singular, but that doesn't sound very attractive. Another alternative
would be to move `resultant()` to a more generic polynomial class that
first tries to use Singular and uses a generic Python implementation in
case that fails.
--
Ticket URL: <http://trac.sagemath.org/ticket/15061#comment:10>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
