Ticket #5562 (closed defect: fixed)
coercion error with vectors and polynomial rings with 1 variable
| Reported by: | ncalexan | Owned by: | was |
|---|---|---|---|
| Priority: | major | Milestone: | sage-5.7 |
| Component: | linear algebra | Keywords: | coercion vector polynomial ring |
| Cc: | robertwb | Work issues: | |
| Report Upstream: | N/A | Reviewers: | Travis Scrimshaw |
| Authors: | Christian Nassau | Merged in: | sage-5.7.beta2 |
| Dependencies: | Stopgaps: |
Description
This is strange: it matters how many variables are specified. This fails and I think this is a bug:
sage: R.<u> = PolynomialRing(RDF, 1, 'u') sage: v1 = vector([u]) sage: v2 = vector([CDF(2)]) sage: v1 * v2 --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/ncalexan/sage-3.4.rc0-sage.math-only-x86_64-Linux/devel/sage/sage/functions/riemann_theta.py in <module>() /home/ncalexan/sage-3.4.rc0-sage.math-only-x86_64-Linux/local/lib/python2.5/site-packages/sage/structure/element.so in sage.structure.el\ ement.Vector.__mul__ (sage/structure/element.c:10435)() /home/ncalexan/sage-3.4.rc0-sage.math-only-x86_64-Linux/local/lib/python2.5/site-packages/sage/structure/coerce.so in sage.structure.coe\ rce.CoercionModel_cache_maps.bin_op (sage/structure/coerce.c:5847)() TypeError: unsupported operand parent(s) for '*': 'Ambient free module of rank 1 over the integral domain Multivariate Polynomial Ring i\ n u over Real Double Field' and 'Vector space of dimension 1 over Complex Double Field'
But both of these succeed:
sage: R.<u, v> = RDF[] sage: v1 = vector([u]) sage: v2 = vector([CDF(2)]) sage: v1 * v2 2.0*u
sage: R.<u> = RDF[] sage: v1 = vector([u]) sage: v2 = vector([CDF(2)]) sage: v1 * v2 2.0*u
Attachments
-
5562.patch
(702 bytes) -
added by cnassau 4 months ago.
Change History
comment:1 Changed 5 months ago by tscrim
- Status changed from new to needs_review
- Report Upstream set to N/A
- Milestone changed from sage-5.6 to sage-duplicate/invalid/wontfix
comment:2 Changed 4 months ago by cnassau
I've attached a patch that adds a doctest that makes sure this keeps working.
The patch also removes plenty of trailing whitespace in the affected file. I got this for free by putting
(add-hook 'before-save-hook 'delete-trailing-whitespace)
into my ".emacs.rc".
But maybe it might have been better to just give the "wontfix" a positive review instead...
comment:3 follow-up: ↓ 4 Changed 4 months ago by tscrim
- Reviewers set to Travis Scrimshaw
- Milestone changed from sage-duplicate/invalid/wontfix to sage-5.7
- Authors set to Christian Nassau
Hey,
For doctest formatting, I would change:
sage: # check that #5562 has been fixed
sage: R.<u> = PolynomialRing(RDF, 1, 'u')
...
to
Check that :trac:`5562` has been fixed::
sage: R.<u> = PolynomialRing(RDF, 1, 'u')
...
I think the trailing whitespace removal should be okay...
Best,
Travis
comment:4 in reply to: ↑ 3 Changed 4 months ago by cnassau
Hi Travis,
I agree, in theory, that the doctest should be reformatted. However, I don't know how to do this because the patch has apparently already been merged in 5.7.beta1. Would I create a new patch based on beta1, or edit the old one?
Cheers, Christian
comment:5 Changed 4 months ago by robertwb
This won't be merged until it's positively reviewed and closed, it's just the target that was changed. You can create a new patch or edit the old, whichever makes it clearer what your changes were.
comment:6 follow-up: ↓ 7 Changed 4 months ago by tscrim
- Status changed from needs_review to positive_review
Looks good to me. Thanks Christian.
comment:7 in reply to: ↑ 6 Changed 4 months ago by cnassau
Replying to tscrim:
Looks good to me. Thanks Christian.
Indeed, my working copy had been garbled, presumably by running "hg import" earlier when I meant "hg qimport" which made me believe that this ticket had somehow magically be merged already... anyway, glad we got rid of this now ;-)
Cheers, Christian
This seems to be fixed in 5.5.rc0