convgauss.m

斯坦福大学的小波的工具箱 比matlab自带的工具箱更完善

function [g,convsig]=convgauss(sig_in,bool)
% congauss -- Convolution of a signal with a gaussian filter.
% Usage
%   convsig=convgauss(sig_in)
% Inputs
%   sig_in	1-d signal.
% Outputs
%   sig_out	1-d filtered signal.
%

n=length(sig_in);
if nargin<2,
	bool=1;
end
 
%t = (1:n)/n;
%sigma = 40/n;
%g = exp(-.5.*(abs(t-.5)./sigma).^2)./sigma./sqrt(pi);
%no=norm(g);
%plot(abs(fft(g)))
%g=1/(no*2*pi) * g;
%g = fftshift(g);
%convsig = iconv(g,sig_in); 

alpha=(2.9)/n;
g=zeros(1,n);
lim=alpha*n;
mult=pi/(2*alpha*n);
g(1:fix(lim))=(cos(mult*(1:fix(lim)))).^2;
g((n/2+1):n)=g((n/2):-1:1);
%g = rnshift(g,n/2);
G=fft(g);
G(n/2+1)=G(n/2);
g=g/abs(G(1));
if bool==-1
	convsig=real(abs(G(1))*ifft(fft(sig_in)./G));
else
	convsig=iconv(g,sig_in);
end

% Written by Maureen Clerc and Jerome Kalifa, 1997
% [e-mail], [e-mail]
    
    
%   
% 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 [e-mail]
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