%裝載數據
load sample.dat -ascii;
xdata=sample;
%d2小波進行5層分解
%一維小波分解
[c,l] = wavedec(xdata,5,'db2');
%重構第1-4層細節系數
d5 = wrcoef('d',c,l,'db2',5);
d4 = wrcoef('d',c,l,'db2',4);
d3 = wrcoef('d',c,l,'db2',3);
d2 = wrcoef('d',c,l,'db2',2);
d1 = wrcoef('d',c,l,'db2',1);
%顯示細節號
figure(2)
subplot(5,1,1);
plot(d1,'LineWidth',2);
ylabel('d1');
subplot(5,1,2);
plot(d2,'LineWidth',2);
ylabel('d2');
subplot(5,1,3);
plot(d3,'LineWidth',2);
ylabel('d3');
subplot(5,1,4);
plot(d4,'LineWidth',2);
ylabel('d4');
subplot(5,1,5);
plot(d5,'LineWidth',2);
ylabel('d5');
xlabel('樣本序號 n');