www.gusucode.com > 小波分析理论与Matlab 7实现 > 小波分析理论与Matlab 7实现/code/Ch16/examp16_8.m
%生成白噪声信号 N=1000; t=1:N; x=rand(1,N)-0.5; figure(1); plot(t,x,'LineWidth',2); xlabel('时间 t/s'); ylabel('幅值 A'); %一维小波分解 [c,l] = wavedec(x,5,'db3'); %重构第1~5层逼近信号 a5 = wrcoef('a',c,l,'db3',5); a4 = wrcoef('a',c,l,'db3',4); a3 = wrcoef('a',c,l,'db3',3); a2 = wrcoef('a',c,l,'db3',2); a1 = wrcoef('a',c,l,'db3',1); %显示各层逼近信号 figure(2) subplot(5,1,1);plot(a5,'LineWidth',2);ylabel('a5'); subplot(5,1,2);plot(a4,'LineWidth',2);ylabel('a4'); subplot(5,1,3);plot(a3,'LineWidth',2);ylabel('a3'); subplot(5,1,4);plot(a2,'LineWidth',2);ylabel('a2'); subplot(5,1,5);plot(a1,'LineWidth',2);ylabel('a1'); xlabel('时间 t/s'); %重构第1~5层细节信号 d5 = wrcoef('d',c,l,'db3',5); d4 = wrcoef('d',c,l,'db3',4); d3 = wrcoef('d',c,l,'db3',3); d2 = wrcoef('d',c,l,'db3',2); d1 = wrcoef('d',c,l,'db3',1); %显示各层细节信号 figure(3) subplot(5,1,1);plot(d5,'LineWidth',2);ylabel('d5'); subplot(5,1,2);plot(d4,'LineWidth',2);ylabel('d4'); subplot(5,1,3);plot(d3,'LineWidth',2);ylabel('d3'); subplot(5,1,4);plot(d2,'LineWidth',2);ylabel('d2'); subplot(5,1,5);plot(d1,'LineWidth',2);ylabel('d1'); xlabel('时间 t/s');