DSP using MATLAB 示例Example3.4

代码：

n = [-1:3]; x = [1:5];       % x(n) = {1,2,3,4,5}
                             %           *
                             %
k = 0:500;
w = (pi/500)*k;              % [0,pi] axis divided into 501 points.
X = x * (exp(-j*pi/500)) .^ (n'*k);

magX = abs(X); angX = angle(X); realX = real(X); imagX = imag(X);

set(gcf,'Color','white');
subplot(2,2,1); plot(k/500,magX); grid on;
title('Magnitude Part');
xlabel('frequency in \pi units'); ylabel('Magnitude');
subplot(2,2,3); plot(k/500, angX/pi); grid on;
title('Angle Part');
xlabel('frequency in \pi units'); ylabel('Radians/\pi');
subplot('2,2,2'); plot(k/500, realX); grid on;
title('Real Part');
xlabel('frequency in \pi units'); ylabel('Real');
subplot('2,2,4'); plot(k/500, imagX); grid on;
title('Imaginary Part');
xlabel('frequency in \pi units'); ylabel('Imaginary');

运行结果：