ex0303b.m

来自「数字信号处理（机械工业出版社）的源码」· M 代码 · 共 13 行

n = -5:5; x = (-0.9).^n; k = -200:200; 
[X,w] = dtft1(x,n,k);
magX = abs(X); angX =angle(X);
subplot(2,1,1); plot(w/pi,magX);grid
axis([-2,2,0,15])
xlabel('frequency in units of pi'); ylabel('|X|')
title('Magnitude Part')
subplot(2,1,2); plot(w/pi,angX)/pi;grid
axis([-2,2,-3,3])
xlabel('frequency in units of pi'); ylabel('radians/pi')
title('Angle Part')