#2420: [with patch, needs work] Extending the gap interface to uni- and
multivariate polynomial rings over number fields
------------------------------------------+---------------------------------
Reporter: SimonKing | Owner: SimonKing
Type: enhancement | Status: needs_work
Priority: major | Milestone: sage-4.5
Component: interfaces | Keywords: gap interface,
polynomial rings, number fields, editor_mhansen
Author: Simon King | Upstream: N/A
Reviewer: | Merged:
Work_issues: Side effect of GAP on Pari |
------------------------------------------+---------------------------------
Changes (by newvalueoldvalue):
* cc: mabshoff (removed)
* cc: wdj, mhansen, davidloeffler (added)
* upstream: => N/A
* work_issues: => Side effect of GAP on Pari
* author: => Simon King
Comment:
I finally resumed work on this ticket. It now depends on #8909 and #9423.
Therefore, I added all people who commented on these tickets as Cc here. I
hope you don't mind.
The things that I announced above are still working (main difference: due
to #8909, Sage's cyclotomic fields are now represented as cyclotomic
fields in GAP).
However, the doctest trouble persist, so, it still is "needs_work". But I
was able to narrow the problem down.
Apparently it is a side effect of GAP on Pari. After two days of work, I
found that it is triggered by two ''different'' doctests in
sage/rings/polynomial/polynomial_element.pyx, namely the test for
{{{_gap_()}}} and for {{{resultant()}}}.
It boils down to the following:
{{{
sage: R.<a, b> = QQ[]
sage: b._pari_() # this is fine
b
sage: R.<y> = GF(7)[]
sage: f = y^3 - 17*y + 5
sage: g = gap(f) # this uses the new patch
sage: f.factor() # this uses pari
(y + 5) * (y + 1)^2
sage: R.<a, b> = QQ[]
sage: b._pari_() # this is a disaster!
Mod(3, 7)
}}}
Does any of you have an explanation for this?
Cheers,
Simon
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/2420#comment:8>
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 post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
