10t.m

来自「包含50个数字信号处理方面的matlab程序」· M 代码 · 共 17 行

clear;
clc;
N=128;
n=0:1:N-1;
t=0.01*n;
x=2*sin(4*pi*t)+5*cos(16*pi*t);
y=x+0.8*randn(1,length(t));
x1=fft(x);
magx1=abs(x1);
w=2*pi/N*n;
subplot(2,1,1);   plot((w*100)/(2*pi),magx1);title('DFT幅度');
axis([0,40,0,400]);
y1=fft(y);
magy1=abs(y1);
w=2*pi/N*n;
subplot(2,1,2);plot((w*100)/(2*pi),magy1);title('被噪声污染后DFT幅度')
axis([0,100,0,400]);