nzeta?



On 06 May 2002 14:00:49 -0400
Raymond Toy <toy@rtp.ericsson.se> wrote:

> 
> In bessel.lisp, there are the functions z-function, nzeta, nzetar, and
> nzetai.  Does any know what these are computing?  I thought it might
> be Riemann's zeta function, but that doesn't seem to be it.
> 

Here is the documentation of bessel.usg
for these functions:

Plasma Dispersion Function, NZETA(Z).

This function is related to the complex error function by

    NZETA(Z) = %I*SQRT(%PI)*EXP(-Z^2)*(1-ERF(-%I*Z))

NZETA(Z)  returns the complex value of the Plasma Dispersion Function for
      complex Z. 

NZETAR(Z)  returns REALPART(NZETA(Z)).

NZETAI(Z)  returns IMAGPART(NZETA(Z)).

Best regards.
-- 
Daniel Duparc <daniel.duparc@free.fr>
29 av. de la Commune de Paris
94400 Vitry sur Seine (France)