function r=gtor(gamma,epsilon)%GTOR	Inverse Levinson-Durbin recursion.%----%USAGE: r=gtor(gamma,epsilon)%%	Finds the autocorrelation sequence r(k) from the %	reflection coefficients gamma.  If the optional input%	epsilon is omitted,%		r=gtor(gamma)%	then the autocorrelation sequence is normalized so %	that r(0)=1.%%  see also ATOG, ATOR, GTOA, RTOA, RTOG%%---------------------------------------------------------------% copyright 1996, by M.H. Hayes.  For use with the book % "Statistical Digital Signal Processing and Modeling"% (John Wiley & Sons, 1996).%---------------------------------------------------------------   p=length(gamma);   aa=gamma(1);   r=[1 -gamma(1)];   for j=2:p;      aa=[aa;0]+gamma(j)*[conj(flipud(aa));1];      r=[r -fliplr(r)*aa];      end;   if nargin == 2,   r = r*epsilon/prod(1-abs(gamma).^2);   end;