Reference

ppoiss(3m)

NAME

ppoiss

DESCRIPTION

function ppoiss.f

source
Bevington, page 39.

purpose
evaluate Poisson probability function

usage
result = ppoiss (nobs, averag)

description of parameters
nobs - number of items observed
averag - mean of distribution

subroutines and function subprograms required
factor (n)
calculates n factorial for integers