getsignal.m

在matlab的小波分析中标,设计一个包含若干不连续点的一维信号

function sig = GetSignal()
	% 引用wavelab中的数据,即A Wavelet Tour of Signal Processing(2nd edition)中fig6.6的信号
	N = 64;
	i = (1:N)./N;
	x = (1-sqrt(i)) + i/2 -.5;
	M = 8*N;
	sig = zeros(1,M);
	sig(M-1.5.*N+1:M-.5*N) = x;
	sig(M-2.5*N+2:M-1.5.*N+1) = x(length(x):-1:1);
	sig(3*N-30:3*N + N) = .5*ones(1,N+31);
	
	t = (1:M)/M;
	sigma = 0.01;
	g = exp(-.5.*(abs(t-.5)./sigma).^2)./sigma./sqrt(2*pi);
	g = fftshift(g);
	
	sig2 = iconv(g',sig)'/M; 
	
	m = max(sig2);
	j = find(sig2 == m);
	sig(8*N/2+1:12*N/2) =  sig2(j:j+2*N-1).*.5./m;
	sig(1:2.5*N) = sig2(M-2.5*N+1:M);
	sig(M-2.5*N+2:M-1.5.*N+1) = x(length(x):-1:1);