%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  shift.m - program shifts x to give y such
%            that y(t)=x(t+delta*T).
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function y=shift(x,delta)
n=length(x); j=round(delta*n);
y=ones(1,n); tmp=ones(1,j);
if j > 0
tmp(1:j)=x(1:j); y(1:n-j)=x(j+1:n); y(n-j+1:n)=tmp(1:j);
elseif j < 0
j=abs(j);
tmp(1:j)=x(n-j+1:n); y(j+1:n)=x(1:n-j); y(1:j)=tmp(1:j);
else; y=x; end