Opened 4 years ago
Last modified 7 days ago
#17511 new defect
Get integral of abs(sin(x)) and abs(cos(x)) right
Reported by: | kcrisman | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-6.5 |
Component: | calculus | Keywords: | abs_integrate |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | Reported upstream. Developers acknowledge bug. | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: | #12731 |
Description (last modified by )
See this comment, discussion in #13364, the supposed fix at https://sourceforge.net/p/maxima/bugs/2520/, this ask.sagemath question, and so forth.
E.g. this is annoying (but apparently right)
(%i1) load(abs_integrate); (%i3) display2d:false; (%o3) false (%i4) integrate(abs(sin(x)),x); (%o4) 4*(abs(sin(x))*(atan(sin(x)/(cos(x)+1))/2 +sin(x)/((cos(x)+1)*(2*sin(x)^2/(cos(x)+1)^2+2))) /abs(cos(x)+1) -(signum(1/(cos(x)+1))*signum(sin(x))*log(2*sin(x)^2/(cos(x)+1)^2+2) -signum(1/(cos(x)+1))*signum(sin(x))*log(sin(x)^2/(cos(x)+1)^2+1) +signum(1/(cos(x)+1))*signum(sin(x)) *(2*sin(x)*atan(sin(x)/(cos(x)+1))/(cos(x)+1) -log(2))) /4)
but it doesn't do the definite integral at all, even the easy ones where abs does nothing on the interval!
Change History (6)
comment:1 Changed 4 years ago by
comment:2 Changed 4 years ago by
- Report Upstream changed from Not yet reported upstream; Will do shortly. to Reported upstream. Developers acknowledge bug.
comment:3 Changed 4 years ago by
- Description modified (diff)
comment:4 Changed 4 years ago by
- Stopgaps set to #12731
comment:5 Changed 4 years ago by
Reported again at https://groups.google.com/forum/#!topic/sage-support/1Hcv29UyqVo
comment:6 Changed 7 days ago by
- Keywords abs_integrate added
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