#20086: rational powers in ZZ[X] and QQ[X]
-------------------------------------+-------------------------------------
Reporter: cheuberg | Owner:
Type: defect | Status: needs_info
Priority: major | Milestone: sage-7.2
Component: basic arithmetic | Resolution:
Keywords: | Merged in:
Authors: Clemens | Reviewers: Benjamin Hackl,
Heuberger, Vincent Delecroix, | Vincent Delecroix
Benjamin Hackl | Work issues:
Report Upstream: N/A | Commit:
Branch: public/20086 | 6f91df97a81fa094c04583314ad38cd5fd199cdb
Dependencies: | Stopgaps:
-------------------------------------+-------------------------------------
Comment (by behackl):
Replying to [comment:60 nbruin]:
> Replying to [comment:59 behackl]:
> > Do you strongly object against setting this back to `positive_review`?
> Yes, because it is parking code in the wrong spot.
>
I was hoping for a comment from Vincent, as he started with the generic
solution on this branch.
In any case: I do not quite understand why this would be in the wrong
place. Unique factorization domains should provide a `factor`-method, and
providing a generic `nth_root` method for them doesn't strike me as bad.
It might be true that this ticket only changes the behavior of polynomial
rings, but I don't see a downside of providing a generic solution. But
maybe I'm missing something? :-)
> Perhaps park your code on
`sage.rings.polynomial.polynomial_element.Polynomial`? Taking an n-th root
of a polynomial via factorization isn't quite as bad as in general.
>
> Since `NumberFieldElement` etc. already provides an `nth_root` method,
it may be sufficient to just provide the method on Polynomial.
Yes, that is true---however, I think that the code provided on this ticket
is generic enough to work for all unique factorization domains. Or doesn't
it? Even if it might be not performant, I think that a generic approach is
certainly allowed to be slow---this can be handled by special case
implementations for special UFDs.
I just don't see a benefit from moving the code back to polynomials only.
Could you elaborate more why this generic solution should be degraded to a
special case?
--
Ticket URL: <http://trac.sagemath.org/ticket/20086#comment:61>
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 https://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
