DESCRIPTION

This is an interface to the Special Function package present in the GNU Scientific Library.

Poly-Gamma Functions

psi(m,x) := (d/dx)^m psi(0,x) = (d/dx)^{m+1} log(gamma(x))

SYNOPSIS

FUNCTIONS

gsl_sf_psi

  Signature: (double x(); double [o]y(); double [o]e())

Di-Gamma Function psi(x).

gsl_sf_psi does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

gsl_sf_psi_1piy

  Signature: (double x(); double [o]y(); double [o]e())

Di-Gamma Function Re[psi(1 + I y)]

gsl_sf_psi_1piy does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

gsl_sf_psi_n

  Signature: (double x(); double [o]y(); double [o]e(); int n)

Poly-Gamma Function psi^(n)(x)

gsl_sf_psi_n does not process bad values. It will set the bad-value flag of all output piddles if the flag is set for any of the input piddles.

AUTHOR

This file copyright (C) 1999 Christian Pellegrin <[email protected]> All rights reserved. There is no warranty. You are allowed to redistribute this software / documentation under certain conditions. For details, see the file COPYING in the PDL distribution. If this file is separated from the PDL distribution, the copyright notice should be included in the file.

The GSL SF modules were written by G. Jungman.