Opened 10 years ago
Last modified 4 years ago
#12145 new defect
Ugly result for exponential integral
Reported by: | mjo | Owned by: | burcin |
---|---|---|---|
Priority: | minor | Milestone: | sage-6.4 |
Component: | calculus | Keywords: | |
Cc: | kcrisman | Merged in: | |
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
As reported in this sage-support thread:
http://groups.google.com/group/sage-support/browse_thread/thread/793c2bdb3db1f02c
We expect,
sage: integral( x / (exp(x) - 1) , (x,0,oo)) pi^2/6
but get,
sage: integral( x / (exp(x) - 1) , (x,0,oo)) -1/6*pi^2 + limit(-1/2*x^2 + x*log(-e^x + 1) + polylog(2, e^x), x, +Infinity)
The above might not be incorrect, but it is not very useful either.
Change History (7)
comment:1 Changed 10 years ago by
- Cc kcrisman added
- Component changed from symbolics to calculus
- Priority changed from major to minor
comment:2 Changed 9 years ago by
comment:3 Changed 8 years ago by
- Milestone changed from sage-5.11 to sage-5.12
comment:4 Changed 7 years ago by
- Milestone changed from sage-6.1 to sage-6.2
comment:5 Changed 7 years ago by
- Milestone changed from sage-6.2 to sage-6.3
comment:6 Changed 7 years ago by
- Milestone changed from sage-6.3 to sage-6.4
comment:7 Changed 4 years ago by
more tests:
sage: giac('integrate(x / (exp(x) - 1), x, 0, inf)') pi^2/6 sage: integrate(x / (exp(x) - 1), x, 0, oo, algorithm='sympy') integrate(x/(e^x - 1), x, 0, +Infinity)
i think this is another reason to make more user friendly the functionality that is offered through giac; stay tuned at the giac interface wiki.
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Same result from Maxima 5.27: