function rho=cyclic_correlation_coefficient(S,tol)%% CYCLIC_CORRELATION_COEFFICIENT%              %              calculates the cyclic correlation coefficient for signal%              from its spectral correlation density%             % USAGE%              rho=cyclic_correlation_coefficient(S,tol)%%              Optional parameter tol can be used to set all%              rho(x,y) to zero if S(x,y) is less than tol% of max(S)% File: cyclic_correlation_coefficient.m% Last Revised: 25/11/97% Created: 25/11/97% Author: Andrew C. McCormick% (C) University of Strathclyde[rows,cols]=size(S);rho=zeros(rows,cols);S=abs(S);mxs=max(max(S));scale_factor=2*cols/rows;for f=1:rows  for a=1:cols    fplus=f+floor(a/scale_factor);    fminus=f-floor(a/scale_factor);    if fplus>rows      fplus=fplus-rows;    end    if fminus<1      fminus=fminus+rows;    end    rho(f,a)=S(f,a)/sqrt(S(fplus,1)*S(fminus,1));  endendif nargin==2  [i,j]=find(S<tol*mxs/100);  for k=1:length(i)    rho(i(k),j(k))=0;  endend