figure_2_20.m

来自「数字信号处理—基于计算机的方法教材上的所有例题源程序」· M 代码 · 共 10 行

% for example 2.10 P50
N = 350;
n = 0:N;
x1 = cos(0.1*pi*n);
x2 = cos(0.01*pi*n);
y  = x1 .* x2;
subplot(311),plot(n,x1);title('x1=cos(0.1*pi*n)');
subplot(312),plot(n,x2);title('x2=cos(0.01*pi*n);');
subplot(313),plot(n,y);title('y=x1 .* x2');
hold on;plot(n,x2,'r');plot(n,-x2,'r');