function [ACF] = acorf(Z,N);
% Autocorrelation function (fast)
% [ACF] = acorf(Z,N);
%
% Input:	Z    Signal
%		N    # of coefficients
% Output:	ACF autocorrelation function

% 	Version 1.21
%	13.02.1996
%	Copyright (c) by Alois Schlögl
%	E-Mail: a.schloegl@ieee.org	

ACF=acovf(Z,N);
ACF = ACF(2:N+1) / ACF(1);
