小波包代码

t1=0:1/50:10-1/50;
f1=[sin(2*pi*t1)+sin(4*pi*t1)+sin(10*pi*t1)];
subplot(3,1,1)
plot(t1,f1,'k')
hold on
t2=10:1/50:20-1/50;
f2=[sin(1.998*pi*t2)+sin(4*pi*t2)+sin(10*pi*t2)];
subplot(3,1,1)
plot(t2,f2,'k')
title('Original signal')
y=fft(f1);
f=(0:length(y)-1)*6/length(y);
subplot(3,1,2);
plot(f,abs(y))  #
fs=50;N=512;
n=0:N-1;t=0:0.02:10-0.02;
x=sin(2*pi*t)+sin(4*pi*t)+sin(10*pi*t);
y=fft(x,N);
mag=abs(y);   
f=n*fs/N;  %频率序列
f=(0:N-1)*fs/N;  %真实频率
subplot(2,1,1);plot(f,mag)
subplot(2,1,2),plot(f(1:N/2),mag(1:N/2));
subplot(2,1,2),plot(f(1:N/2),mag(1:N/2)*2/N);   %真实幅值
hold on
fs=50;N=512;
n=0:N-1;t=0:0.02:10-0.02;
x=sin(1.998*pi*t)+sin(4*pi*t)+sin(10*pi*t);
y=fft(x,N);
mag=abs(y);