#12541: Remove Sequence test in span
------------------------------+---------------------------------------------
Reporter: novoselt | Owner: jason, was
Type: defect | Status: needs_info
Priority: minor | Milestone: sage-5.0
Component: linear algebra | Keywords:
Work_issues: | Upstream: N/A
Reviewer: Rob Beezer | Author: Andrey Novoseltsev
Merged: | Dependencies:
------------------------------+---------------------------------------------
Changes (by rbeezer):
* status: needs_review => needs_info
Comment:
I find the error message in the doctest still somewhat cryptic. Here's a
simplified explanation of what happens:
{{{
sage: span(QQ, [0])
---------------------------------------------------------------------------
AttributeError Traceback (most recent call
last)
<snip>
AttributeError: 'sage.rings.integer_ring.IntegerRing_class' object has no
attribute 'span'
}}}
It appears that the span() '''function''' in free_module.pyx mostly tries
to find an appropriate parent for the generators, and then hands
everything off to the .span() '''method''' of the parent.
So here, the integer zero is construed to be the first generator, and the
class of integers has no span method.
What do you think of checking if the first generator is a list, or if it
is a free module element (`is_FreeModuleElement`), before proceeding with
a supposed parent? This would allow an informative error message, such as
- "generators must be lists of ring elements, or free module elements"
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/12541#comment:14>
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.
