Visualise frequency confusing/aliasing due to sampling of a pure sinusoid as a video.

frequency_confusion.m

clear all; close all;

n = [0:0.1:50];
w = pi/2;
Ts = 0.2;
ks = [-200:200];

y = zeros(size(n))

frame_count = 1;

for k = ks
    y = y + cos(w*n*Ts + 2*pi*k*n);
    if ((mod(k, 10) == 3) || (k < 10))
        plot(n, y/max(y))
        F(frame_count) = getframe(gcf);
        frame_count = frame_count + 1;
    end
end


vid = VideoWriter('result.mp4');
open(vid);
writeVideo(vid, F);
close(vid)