examp3_53.m

matlab的大量实例代码

h=0.01; t=0:h:1;
x=12*sin(2*pi*10*t+pi/4)+5*cos(2*pi*40*t);
X=fft(x); f=t/h;
plot(f(1:floor(length(f)/2)),abs(X(1:floor(length(f)/2))))

ix=real(ifft(X)); plot(t,x,t,ix,':')
norm(x-ix)