Zeroth-order Bessel function Python

Question

Apologies for the simplicity of this question.

I would like to implement an equation in Python. In this equation, K_0 is the zeroth-order modifed Bessel function.

What is the best way of implementing K_0 in Python?

Answer 1

No need to implement it; it's included. See the docs for the scipy.special module, in particular the optimized common ones here:

>>> import scipy.special
>>> print scipy.special.k0.__doc__
k0(x[, out])

y=k0(x) returns the modified Bessel function of the second kind (sometimes called the third kind) of
order 0 at x.
>>> scipy.special.k0(1)
0.42102443824070823

or more generally:

>>> print scipy.special.kn.__doc__
kn(x1, x2[, out])

y=kn(n,x) returns the modified Bessel function of the second kind (sometimes called the third kind) for
integer order n at x.
>>> scipy.special.kn(0, 1)
0.42102443824070834