#4539: plural wrapper
---------------------------+------------------------------------------------
Reporter: burcin | Owner: OleksandrMotsak, AlexanderDreyer
Type: enhancement | Status: needs_work
Priority: major | Milestone: sage-4.7.2
Component: algebra | Keywords: libsingular plural wrapper sd34
Work_issues: | Upstream: N/A
Reviewer: | Author:
Merged: | Dependencies:
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Comment(by SimonKing):
Replying to [comment:50 SimonKing]:
> sage: P.<x,y,z> = QQ[]
> sage: x/0
> Traceback (most recent call last):
> ...
> ZeroDivisionError:
Here is the explanation:
Let `P = QQ[x,y,z]`. Since coercion is now done properly, x/0 is first
converting 0 into P and tries to invert it there. The result is a naked
`ZeroDivisionError` in
sage.libs.singular.polynomial.singular_polynomial_div_coeff.
Before, it used to invert 0 as a rational number, resulting in a
`ZeroDivisionError` with some error message.
Burcin and I agree that it is ok to have the `ZeroDivisionError` without a
message: What else could it state but "don't divide by zero"?
So, it is not an issue.
> {{{
> sage: (x*y).is_monomial()
> True
> sage: (2*y).is_monomial()
> False
I don't know why it has occured in the first place, but now it seems
alright, even with my patch.
> {{{
> sage: (x+y^2^30)^10
> x^10
> }}}
> --> That should result in an overflow error.
It turns out that one gets the ''same'' stupid result with an unpatched
sage-4.7.2.alpha2. Burcin told me that this patch is supposed to fix it.
Apparently it fails, and we need to understand why it fails.
> I didn't analyse the segmentation faults.
That will be next...
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4539#comment:52>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
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