[Numpy-discussion] no ordinary Bessel functions?

Anne Archibald peridot.faceted@gmail....
Tue Dec 15 09:32:55 CST 2009

2009/12/14 Dr. Phillip M. Feldman <pfeldman@verizon.net>:
> When I issue the command
> np.lookfor('bessel')
> I get the following:
> Search results for 'bessel'
> ---------------------------
> numpy.i0
>    Modified Bessel function of the first kind, order 0.
> numpy.kaiser
>    Return the Kaiser window.
> numpy.random.vonmises
>    Draw samples from a von Mises distribution.
> I assume that there is an ordinary (unmodified) Bessel function in NumPy,
> but have not been able to figure out how to access it. Also, I need to
> operate sometimes on scalars, and sometimes on arrays. For operations on
> scalars, are the NumPy Bessel functions significantly slower than the SciPy
> Bessel functions?

I am afraid this is one of the historical warts in numpy. The proper
place for special functions is in scipy.special, which does indeed
have various flavours of Bessel functions.


More information about the NumPy-Discussion mailing list