Opened 6 years ago
Last modified 2 years ago
#17469 new defect
Maxima doesn't do an integral we thought was fixed
Reported by: | kcrisman | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-6.5 |
Component: | calculus | Keywords: | |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | Fixed upstream, but not in a stable release. | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
#11238 is back.
;;; Loading #P"/Users/.../sage/local/lib/ecl/sb-bsd-sockets.fas" ;;; Loading #P"/Users/.../sage/local/lib/ecl/sockets.fas" ;;; Loading #P"/Users/.../sage/local/lib/ecl/defsystem.fas" ;;; Loading #P"/Users/.../sage/local/lib/ecl/cmp.fas" Maxima 5.34.1 http://maxima.sourceforge.net using Lisp ECL 13.5.1 Distributed under the GNU Public License. See the file COPYING. Dedicated to the memory of William Schelter. The function bug_report() provides bug reporting information. (%i1) display2d:false ; (%o1) false (%i2) integrate(exp(-x)*sinh(sqrt(x)),x,0,inf); (%o2) -%e^(1/4)*(2*gamma_incomplete(1,1)-gamma_incomplete(1/2,1)-sqrt(%pi)-2)/4 +%e^(1/4)*gamma_incomplete(1,1)/2-%e^(1/4)*gamma_incomplete(1/2,1)/4 +%e^(1/4)*sqrt(%pi)/4-%e^(1/4)/2 (%i3) domain:complex; (%o3) complex (%i4) integrate(exp(-x)*sinh(sqrt(x)),x,0,inf); ^C Maxima encountered a Lisp error: Console interrupt. Automatically continuing.
Change History (6)
comment:1 Changed 6 years ago by
comment:2 Changed 6 years ago by
- Summary changed from Maxima hangs on an integral we thought was fixed to Maxima doesn't do an integral we thought was fixed
comment:3 Changed 6 years ago by
- Report Upstream changed from N/A to Reported upstream. No feedback yet.
comment:4 Changed 6 years ago by
Current doctest for this bites.
Another symbolic integral, from :trac:`11238`, that used to return zero incorrectly; with Maxima 5.26.0 one gets ``1/2*sqrt(pi)*e^(1/4)``, whereas with 5.29.1, and even more so with 5.33.0, the expression is less pleasant, but still has the same value. Unfortunately, the computation takes a very long time with the default settings, so we temporarily use the Maxima setting ``domain: real``:: sage: sage.calculus.calculus.maxima('domain: real') real sage: f = exp(-x) * sinh(sqrt(x)) sage: t = integrate(f, x, 0, Infinity); t # long time 1/4*sqrt(pi)*(erf(1) - 1)*e^(1/4) - 1/4*(sqrt(pi)*(erf(1) - 1) - sqrt(pi) + 2*e^(-1) - 2)*e^(1/4) + 1/4*sqrt(pi)*e^(1/4) - 1/2*e^(1/4) + 1/2*e^(-3/4) sage: t.simplify_exp() # long time 1/2*sqrt(pi)*e^(1/4) sage: sage.calculus.calculus.maxima('domain: complex') complex
And the 'long time' is not kidding.
comment:5 Changed 6 years ago by
- Report Upstream changed from Reported upstream. No feedback yet. to Fixed upstream, but not in a stable release.
Apparently fixed again upstream, though still looooong time...
comment:6 Changed 2 years ago by
Sorry, wrong ticket (and I don't know how to delete a comment in Trac...)
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To be precise,
This did work in Sage 5.2.