#17469: Maxima doesn't do an integral we thought was fixed
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Reporter: kcrisman | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.5
Component: calculus | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: Reported upstream. No | Work issues:
feedback yet. | Commit:
Branch: | Stopgaps:
Dependencies: |
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Comment (by kcrisman):
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.
--
Ticket URL: <http://trac.sagemath.org/ticket/17469#comment:4>
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