#18940: Polynomials ignore the step argument in __getitem__
-------------------------------------+-------------------------------------
Reporter: pbruin | Owner:
Type: defect | Status: needs_info
Priority: major | Milestone: sage-6.10
Component: algebra | Resolution:
Keywords: | Merged in:
Authors: Peter Bruin | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/pbruin/18940-getitem_step | 1c56779b3140d12fbe5d0973cdcad0ac9dbb8054
Dependencies: #19409 | Stopgaps:
-------------------------------------+-------------------------------------
Comment (by tscrim):
Replying to [comment:23 jdemeyer]:
> Replying to [comment:22 tscrim]:
> > I personally would find that the degree was lowered more surprising
> So what's in your opinion the correct answer for
> {{{
> sage: pol = PolynomialRing(QQ, 'x')(range(10))
> sage: list(pol[2::2])
> }}}
That depends on if we want a slice of a polynomial returns a polynomial or
a simple list of the coefficients. I am (very) slightly in favor of
returning a polynomial, so with that `[0, 2, 4, 6, 8]`.
> If we cannot agree on a "natural" definition for `pol[a:b:c]`, perhaps
the best compromise is simply
> {{{
> if isinstance(i, slice):
> raise NotImplementedError("polynomial slicing is not defined")
> }}}
This would be okay with me as well, but I don't think my opinion here
should weigh very much here because I am mostly ambivalent about this
behavior since I don't have a use for it.
--
Ticket URL: <http://trac.sagemath.org/ticket/18940#comment:24>
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.
