#11143: define symbolic functions for exponential integrals
-------------------------------------------------------------+--------------
Reporter: kcrisman | Owner:
benjaminfjones
Type: defect | Status:
needs_review
Priority: major | Milestone:
sage-5.1
Component: symbolics | Resolution:
Keywords: ei Ei special function maxima sd32 sd40.5 | Work issues:
Report Upstream: N/A | Reviewers:
Burcin Erocal, Karl-Dieter Crisman
Authors: Benjamin Jones | Merged in:
Dependencies: | Stopgaps:
-------------------------------------------------------------+--------------
Comment (by dsm):
Thanks, kcrisman. Since after real-world discussions it appears that the
integration difficulty is another Maxima quirk, I don't think we should
hold up approving this, especially because it can be worked around. I do
think it's worth warning the user, and the example will serve as a
reminder to us that it can be removed when we update to a version of
Maxima which finally fixes it, 'cause the doctest will fail.
So I propose adding the following to EXAMPLES for sinh_integral:
{{{
Note that due to some problems with the way Maxima handles these
expressions, definite integrals can sometimes give unexpected
results (typically when using inexact endpoints) due to
inconsistent branching::
sage: integrate(sinh_integral(x), x, 0, 1/2)
-cosh(1/2) + 1/2*sinh_integral(1/2) + 1
sage: integrate(sinh_integral(x), x, 0, 1/2).n() # right
0.125872409703453
sage: integrate(sinh_integral(x), x, 0, 0.5).n() # wrong!
0.125872409703453 + 1.57079632679490*I
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11143#comment:53>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
