irfpy.util.kappa

Kappa distribution.

Code author: Yoshifumi Futaana

class irfpy.util.kappa.kappa_distribution(kappa, ni=1, Ti=11604.0, mi=1.67262192595e-27)

Bases: object

Kappa distribution expressed by

$$f_i^{\kappa }(r,v)=\frac{n_i}{2\pi (\kappa w_{\kappa i}^2{)}^{3/2}}\frac{\mathrm{\Gamma }(\kappa +1)}{\mathrm{\Gamma }(\kappa -1/2)\mathrm{\Gamma }(3/2)}(1+\frac{v^2}{\kappa w_{\kappa i}^2}{)}^{-(\kappa +1)}$$

Here $w_{\kappa i}^2=(2\kappa -3)k{T}_i/\kappa mi$

In this class, use of MKSA unit system is implicitly assumed.

>>> fk2 = kappa_distribution(2)    # Returned is the function.  f(v, k=2)
>>> fk2_at0 = fk2(0)     # f(0, k=2) is returned.

Warning

Not yet fully tested.

Todo

Validate the formulation.

irfpy.util.kappa.doctests()