[issue3366] Add gamma function, error functions and other C99 math.h functions to math module
Mark Dickinson
report at bugs.python.org
Sun Dec 13 13:53:48 CET 2009
Mark Dickinson <dickinsm at gmail.com> added the comment:
nirinA: thanks for the erf patch. It's fine as far as it goes; the main
technical issue is that the series development only converges at a
sensible rate for smallish x; for larger x something more is needed.
Here's a prototype patch for the erf and erfc functions that uses a power
series (not quite the same as the series nirinA used; by pulling out a
factor of exp(-x*2) you can make all coefficients in the remaining series
positive, which is good for the numerics) for small x, and a continued
fraction expansion for larger x. The erf and erfc functions are
currently written in Python. I'll do some more testing (and possibly
tweaking) of this patch and then translate the Python to C.
----------
Added file: http://bugs.python.org/file15539/erf.patch
_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue3366>
_______________________________________
More information about the Python-bugs-list
mailing list