#17675: xgcd(2,2) hangs forever in ZZ['x']
-------------------------------------+-------------------------------------
Reporter: vdelecroix | Owner:
Type: defect | Status: needs_review
Priority: critical | Milestone: sage-6.5
Component: algebra | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: Reported | Work issues:
upstream. Developers deny it's a | Commit:
bug. | f0d7ca3a02d79b66820aad2289ba5d0809ec9c3e
Branch: | Stopgaps:
u/vdelecroix/17675 |
Dependencies: |
-------------------------------------+-------------------------------------
Description changed by vdelecroix:
Old description:
> On sage-6.5.beta6 we have
> {{{
> sage: R.<x> = ZZ['x']
> sage: R(2).xgcd(R(2)) # be prepared to wait
> }}}
> Seems to be a problem in FLINT (the function `fmpz_poly_xgcd`). See this
> [https://github.com/wbhart/flint2/issues/112 bug report].
>
> As soon as the issue is fixed on the FLINT side, we should add the above
> test somewhere in Sage (probably in the xgcd function of integer
> polynomials).
New description:
On sage-6.5.beta6 we have
{{{
sage: R.<x> = ZZ['x']
sage: R(2).xgcd(R(2)) # be prepared to wait
}}}
It is a problem in our way to use the FLINT function `fmpz_poly_xgcd`. As
Bill reported on [https://groups.google.com/forum/#!topic/sage-
devel/pDXdjGVvap8 this sage-devel thread] it does not work for input which
are constant polynomials (note that it is already a bit more general that
what is indicated in FLINT documentation: ''the function assumes that f
and g are primitive (have Gaussian content equal to 1). The result is
undefined otherwise.'')
See also this [https://github.com/wbhart/flint2/issues/112 FLINT bug
report].
--
--
Ticket URL: <http://trac.sagemath.org/ticket/17675#comment:9>
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.
