Ticket #11238 (closed defect: fixed)

Opened 2 years ago

Last modified 10 months ago

failing calculation of a symbolic integral

Reported by: casamayou Owned by: burcin
Priority: major Milestone: sage-5.0
Component: calculus Keywords: integrate
Cc: zimmerma, kcrisman Work issues:
Report Upstream: Fixed upstream, in a later stable release. Reviewers: Karl-Dieter Crisman
Authors: Michael Orlitzky Merged in: sage-5.0.beta12
Dependencies: #11445 Stopgaps:

Description

With a symbolic calculation, Sage returns 0 for the integral integrate(exp(-x)*sinh(sqrt(x)), x, 0, oo) instead of exp(1/4) * sqrt(pi) / 2 

sage: integrate(exp(-x)*sinh(sqrt(x)), x, 0, oo)
0
sage: integral_numerical(exp(-x)*sinh(sqrt(x)), 0, oo)
(1.1379378972322944, 3.1822014179283542e-07)
sage: (exp(1/4) * sqrt(pi) / 2).n()
1.13793789723437
sage: plot(exp(-t)*sinh(sqrt(t)), t, 0, 10)

Attachments

sage-trac_11238.patch Download (983 bytes) - added by mjo 14 months ago.
Add a doctest for the non-zero result.

Change History

comment:1 Changed 2 years ago by kcrisman

  • Report Upstream changed from N/A to Reported upstream. Little or no feedback.

This is also present in the latest Maxima. This is now reported at  this Maxima bug artifact. 

Maxima 5.24.0 http://maxima.sourceforge.net
using Lisp SBCL 1.0.24
(%i3) integrate(exp(-x)*sinh(sqrt(x)),x,0,inf);
(%o3) 0
(%i4) quad_qagi(exp(-x)*sinh(sqrt(x)),x,0,inf);
(%o4) [1.137937897234377, 5.171862937913829e-11, 345, 0]

comment:2 Changed 16 months ago by kcrisman

  • Report Upstream changed from Reported upstream. Little or no feedback. to Fixed upstream, in a later stable release.

This is NOT fixed in 5.24, so we can't yet do it, but it is now fixed in Maxima 5.26. 

(%i2) display2d:false;

(%o2) false
(%i3) integrate(exp(-x)*sinh(sqrt(x)),x,0,inf);

(%o3) %e^(1/4)*sqrt(%pi)/2

Changed 14 months ago by mjo

Add a doctest for the non-zero result.

comment:3 Changed 14 months ago by mjo

  • Cc kcrisman added
  • Status changed from new to needs_review
  • Authors set to Michael Orlitzky

Here's another one I found fixed by the Maxima upgrade. The patch will apply cleanly on top of #11445. I put the test in the same place as that one, but I could of course copy/paste them out together.

comment:4 Changed 14 months ago by kcrisman

  • Status changed from needs_review to positive_review
  • Reviewers set to Karl-Dieter Crisman
  • Dependencies set to #11445

Looks good. No worries about the cut/paste. However, let's try to put others in the symbolic integration ones... Maybe we should even separate some of them out into one of our "tests" files in calculus/ or something.

comment:5 Changed 14 months ago by jdemeyer

  • Status changed from positive_review to closed
  • Resolution set to fixed
  • Merged in set to sage-5.0.beta12

comment:6 Changed 12 months ago by mjo

This seems to be back with maxima-5.27.0, but only with domain: complex; 

Maxima 5.27.0 http://maxima.sourceforge.net
using Lisp ECL 12.2.1
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)*sqrt(%pi)/2
(%i3) domain:complex;

(%o3) complex
(%i4) integrate(exp(-x)*sinh(sqrt(x)),x,0,inf);

(%o4) 0

Reported upstream at  https://sourceforge.net/tracker/?func=detail&aid=3529144&group_id=4933&atid=104933.

comment:7 Changed 12 months ago by zimmerma

thank you Michael, the new doctest will bump when/if we upgrade to Maxima 5.27.

Paul

comment:8 Changed 10 months ago by mjo

This is fixed upstream, again. It should make it into maxima-5.28.

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