%調入含突變點的信號
load freqbrk;
x=freqbrk;
N=length(x);
t=1:N;
figure(1);
plot(t,x,'LineWidth',2);xlabel('時間 t/s');ylabel('幅值 A');
%一維小波分解
[c,l] = wavedec(x,6,'db5');
%重構第6層逼近系數
a6 = wrcoef('a',c,l,'db5',6);
%重構第1～6層細節系數
d6 = wrcoef('d',c,l,'db5',6);
d5 = wrcoef('d',c,l,'db5',5);
d4 = wrcoef('d',c,l,'db5',4);
d3 = wrcoef('d',c,l,'db5',3);
d2 = wrcoef('d',c,l,'db5',2);
d1 = wrcoef('d',c,l,'db5',1);
%顯示重構系數和細節系數
figure(2)
subplot(7,1,1);plot(d6,'LineWidth',2);ylabel('d6');
subplot(7,1,2);plot(d5,'LineWidth',2);ylabel('d5');
subplot(7,1,3);plot(d4,'LineWidth',2);ylabel('d4');
subplot(7,1,4);plot(d3,'LineWidth',2);ylabel('d3');
subplot(7,1,5);plot(d2,'LineWidth',2);ylabel('d2');
subplot(7,1,6);plot(d1,'LineWidth',2);ylabel('d1');
subplot(7,1,7);plot(a6,'LineWidth',2);ylabel('a6');
xlabel('時間 t/s');