#4807: bug in exponential integral
----------------------+-----------------------------------------------------
Reporter: wdj | Owner: burcin
Type: defect | Status: new
Priority: major | Milestone: sage-3.4.1
Component: calculus | Resolution:
Keywords: |
----------------------+-----------------------------------------------------
Comment (by fredrik.johansson):
The exponential integral implementation in mpmath was recently improved to
work for large arguments too:
{{{
>>> mp.dps = 50
>>> ei(mpc(10**30, 10**40))
mpc(real='-2.2944454721211223524123643204705731535186663746073664e+4342944819032
51827651128918876',
imag='3.310554099386694677220121243704912443715898934912981e
+434294481903251827651128918876')
}}}
However, it is not optimized at all at the moment, and is probably many
times slower than PARI. ei in mpmath is about 4-8 times slower than the
cosine integral ci (which is almost the same function as ei, so properly
optimized they should be about equally fast). [mpmath.ci(x) for x in
range(10**6)] takes 132 seconds on my laptop.
If I find the time, I'll try to both optimize and assure accuracy
everywhere for all the incarnations of exponential, trigonometric and
hyperbolic integrals in mpmath for the next version.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4807#comment:4>
Sage <http://sagemath.org/>
Sage - Open Source Mathematical Software: Building the Car Instead of
Reinventing the Wheel
--~--~---------~--~----~------------~-------~--~----~
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
-~----------~----~----~----~------~----~------~--~---
