bgfft.m

数字信号分析处理方面的好教材,有DSP的MATLAB源程序.

k=[1:1:1000];
x1=sin(2*pi*5*k*0.001);
x2=sin(2*pi*50*k*0.001);
x3=sin(2*pi*400*k*0.001);
x4=1.5*randn(1,length(k));
x=x1+x2+x3;

X=fft(x,512);

magX=abs(X);
f=1000*(0:255)/512;
plot(f,magX(1:256))