Opened 5 years ago
Closed 3 years ago
#23271 closed defect (duplicate)
Wrong integration of abs(sin(x)*cos(x))
| Reported by: | pdenapo | Owned by: | |
|---|---|---|---|
| Priority: | major | Milestone: | sage-duplicate/invalid/wontfix |
| Component: | symbolics | Keywords: | symbolic integration, absolute value, abs_integrate |
| Cc: | Merged in: | ||
| Authors: | Reviewers: | ||
| Report Upstream: | N/A | Work issues: | |
| Branch: | Commit: | ||
| Dependencies: | Stopgaps: |
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Description (last modified by )
Sage ignores the absolute value in the following symbolic integration.
sage: g=abs(sin(x)*cos(x)) sage: g.integrate(0,2*pi) 0
(the right result is 2, the integrand is positive in the interval so the integral can never be 0!
sage: version() 'SageMath version 7.6, Release Date: 2017-03-25'
Change History (6)
comment:1 Changed 5 years ago by
- Description modified (diff)
comment:2 follow-up: ↓ 3 Changed 5 years ago by
comment:3 in reply to: ↑ 2 Changed 5 years ago by
- Summary changed from Wrong intergation of abs(sin(x)*cos(x)) to Wrong integration of abs(sin(x)*cos(x))
Replying to mforets:
(should we submit a new upstream report for this one? since they seem to be so related).
Don't think so.
comment:4 Changed 3 years ago by
- Keywords abs_integrate added
comment:5 Changed 3 years ago by
fixed by #27958, that needs review
comment:6 Changed 3 years ago by
- Milestone changed from sage-8.0 to sage-duplicate/invalid/wontfix
- Resolution set to duplicate
- Status changed from new to closed
already doctested in #27958
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from v.8.0 those abs-integrands can be handled with the Giac interface:
besides, there are several related tickets in the symbolic wiki -- integration. there is a link to one Maxima's upstream report in #17511 (should we submit a new upstream report for this one? since they seem to be so related).