function [b2,a2,nu2]=z_rev(b,a,nu);
%	[b2,a2,nu2]=z_rev(b,a,nu)
%  Compute the parameterization for the
%  time reversal:  G(z)=H(1/z)
	b2=flipud(b')';a2=flipud(a')';
	c=1/a2(1);
	b2=c*b2;a2=c*a2;
	nu2=length(b)-length(a)-nu;