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/Ch10/exam10_13.m
clc; clear; load noisbloc s= noisbloc(1:1024); ls=length(s); [cA1,cD1]=dwt(s,'db4'); A1=upcoef('a',cA1,'db4',1,ls); D1=upcoef('d',cD1,'db4',1,ls); subplot(2,1,1);plot(A1);title('低频A1') subplot(2,1,2);plot(D1);title('高频D1') A0=idwt(cA1,cD1,'db4',ls); figure(2) subplot(2,1,1);plot(s);title('原始信号') subplot(2,1,2);plot(A0);title('重构信号') [C,L]=wavedec(s,5,'db4'); cA5=appcoef(C,L,'db4',5); A5=wrcoef('a',C,L,'db4',3); D1=wrcoef('d',C,L,'db4',1); D2=wrcoef('d',C,L,'db4',2); D3=wrcoef('d',C,L,'db4',3); D4=wrcoef('d',C,L,'db4',4); D5=wrcoef('d',C,L,'db4',5); subplot(3,2,1);plot(A5);title('低频A5') subplot(3,2,2);plot(D1);title('高频D1') subplot(3,2,3);plot(D2);title('高频D2') subplot(3,2,4);plot(D3);title('高频D3') subplot(3,2,5);plot(D3);title('高频D4') subplot(3,2,6);plot(D3);title('高频D5') figure(3) A0=waverec(C,L,'db4'); subplot(3,1,1);plot(s);title('原始信号') subplot(3,1,2);plot(A0);title('重构信号') subplot(3,1,3);plot(s-A0);title('误差信号') err = max(abs(s-A0))