Opened 8 years ago
Last modified 5 years ago
#12240 new defect
Multivariate powerseries with symbolic coefficients issues
Reported by: | vbraun | Owned by: | malb |
---|---|---|---|
Priority: | major | Milestone: | sage-6.4 |
Component: | commutative algebra | Keywords: | multivariate power series |
Cc: | niles | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
Multivariate powerseries over SR seem to work, but coercion does not. For example, the coercion from ZZ to QQ works fine:
sage: T.<a,b> = PowerSeriesRing(ZZ,2) sage: f = 1 + a + b + a*b + T.O(5) sage: 1/2 * f 1/2 + 1/2*a + 1/2*b + 1/2*a*b + O(a, b)^5
but the same thing fails with SR:
sage: exp(2) * f --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/vbraun/opt/sage-4.8.alpha4/devel/sage-main/sage/schemes/generic/<ipython console> in <module>() /home/vbraun/opt/sage-4.8.alpha4/local/lib/python2.6/site-packages/sage/structure/element.so in sage.structure.element.RingElement.__mul__ (sage/structure/element.c:12158)() /home/vbraun/opt/sage-4.8.alpha4/local/lib/python2.6/site-packages/sage/structure/coerce.so in sage.structure.coerce.CoercionModel_cache_maps.bin_op (sage/structure/coerce.c:7467)() TypeError: unsupported operand parent(s) for '*': 'Symbolic Ring' and 'Multivariate Power Series Ring in a, b over Integer Ring'
Also, manually changing the base ring brings out the background polynomial variable:
sage: f.change_ring(SR) (Tbg*a*b + a + b)*Tbg + 1 + O(a, b)^5
Change History (4)
comment:1 Changed 6 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:2 Changed 5 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:3 Changed 5 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:4 Changed 5 years ago by
- Milestone changed from sage-6.3 to sage-6.4
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