#17671: Implement xgcd for fraction fields
-------------------------------------+-------------------------------------
Reporter: vdelecroix | Owner:
Type: defect | Status: needs_review
Priority: major | Milestone: sage-6.5
Component: basic arithmetic | Resolution:
Keywords: | Merged in:
Authors: Vincent Delecroix | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
u/vdelecroix/17671 | 401193ce270c603dc80ebc1028ff46d0eb662c6c
Dependencies: #17673 | Stopgaps:
-------------------------------------+-------------------------------------
Comment (by vdelecroix):
Replying to [comment:9 bruno]:
> * In `src/sage/rings/arith.py`, lines 1901-1910, the introducing
sentence should to my mind be:
right
> * I do not understand exactly what you want to do with your function
`_test_gcd_vs_xgcd()`: As discussed, it is not clear that the results
should always be the same.
The test is '''only''' for principal ideal domains. Up to now I
encountered two cases where the convention are a bit special:
- quotient fields: the gcd/xgcd is compatible with the ring (managed by
the category)
- polynomial over fields: the gcd/xgcd always return monic polynomials
(managed by the methods in `rings.polynomial.polynomial_element_generic`)
If there is an example of a PID where gcd and xgcd '''must''' be different
I would be happy to remove my test.
Vincent
--
Ticket URL: <http://trac.sagemath.org/ticket/17671#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.
