Opened 6 years ago
Last modified 5 years ago
#19998 new defect
Check for and handle symbolic series in simplify
Reported by: | dkrenn | Owned by: | |
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Priority: | major | Milestone: | sage-7.4 |
Component: | symbolics | Keywords: | |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
sage: (x+1).series(x,2) 1 + 1*x sage: (x+1).series(x,2).operator() is None True sage: (x+1).series(x,2).operands() [1, x]
Related (maybe a consequence) is
sage: (x+1).series(x,2) - 1 (1 + 1*x) - 1 sage: ((x+1).series(x,2) - 1).simplify() ... ValueError: The name "1" is not a valid Python identifier.
Change History (2)
comment:1 Changed 5 years ago by
comment:2 Changed 5 years ago by
- Milestone changed from sage-7.1 to sage-7.4
- Summary changed from missing operator in symbolic series to Check for and handle symbolic series in simplify
The best way to give users what they want---apart from always automatically applying the series operator---would be to apply it in simplify()
if the expression has a series, i.e., ((x+1).series(x,2) - 1).simplify()
should give 1*x
instead of an exception. This means that the operator to-be-applied should have as precision the min of all operators precisions in the expression.
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It is both a consequence of the special status series have in GiNaC. As to the latter, the documentation notes you need to apply series again for getting results: