www.pudn.com > TimeFrequency.rar > Interpol2.m

function g = Interpol2(f); 
% 
% Interpolates signal f (length N ) to a signal g (length 2N) 
% such that g(2*n) = f(n) 
% 
% 
	f0   = f; 
	f    = f(:); 
	N    = length(f); 
	hatf = fft(f); 
	hatg = zeros(2*N,1); 
	hatg(1:N/2)     = 2*hatf(1:N/2); 
	hatg(3*N/2+2:2*N) = 2*hatf(N/2+2:N); 
	hatg(N/2+1)=hatf(N/2+1); 
	hatg(3*N/2+1)=hatf(N/2+1);	 
	g = ifft(hatg); 
	g = ShapeLike(g,f0); 
	 
% Written by Maureen Clerc and Jerome Kalifa, 1997 
% clerc@cmapx.polytechnique.fr, kalifa@cmapx.polytechnique.fr 
     
     
%    
% Part of WaveLab Version 802 
% Built Sunday, October 3, 1999 8:52:27 AM 
% This is Copyrighted Material 
% For Copying permissions see COPYING.m 
% Comments? e-mail wavelab@stat.stanford.edu 
%