fourier.m

来自「一个能离散FFT的MATLAB综合运用题,做的不好」· M 代码 · 共 15 行

N=get(handles.edit1,'string');
 n=[0:N-1];
 T=get(handles.edit2,'string');
 T=str2num(char(T));
 t=n*T;
x=sin(1.5*pi*t)+0.5*cos(3*pi*t);
y=x+2*randn(size(t));
Y=fft(y,512);
pyy=Y.*conj(Y)/512;
f=1000*(0:256)/512;
figure;
plot(f,pyy(1:257))
title('Frequency content of y')
xlabel('Frequency (Hz)')
grid;