% fig28
clear;clc;close all;
N=512;
z=zeros(1,N);
z(1,[1:64])=1-([0:63]/64);
z(1,[257:320])=1-([0:63]/64);
plot(z);axis tight

N=4;
[c,l] = wavedec(z,N,'db6');
ca4 = appcoef(c,l,'db6',4);
cd4 = detcoef(c,l,4);
cd3 = detcoef(c,l,3);
cd2 = detcoef(c,l,2);
cd1 = detcoef(c,l,1);

figure;plot(cd1,'x');axis tight;
figure;plot(cd2,'x');axis tight;
figure;plot(cd3,'x');axis tight;
figure;plot(cd4,'x');axis tight;
figure;plot(ca4,'x');axis tight;