% 3D plot of a figure picturing complex signals
% M. Barbeau, Dec. 5, 2003
t = 0:pi/50:10*pi;
% Generate a vector of zeroes
ZV = zeros(1,length(t));
% plot e^2 \phi f t
plot3(cos(t),sin(t),t);
axis equal;
axis square; grid on;
hold on;
% projection on time and real plane
plot3(cos(t),ZV+3,t,'--');
% projection on time and imaginary plane
plot3(ZV+3,sin(t),t,'--');
axis ([-3 3 -3 3 0 32]);
xlabel('Real');
ylabel('Imaginary');
zlabel('Time');
text(3, 0, 33,  'sin 2 \pi f t');
text(1, 3, 33,  'cos 2 \pi f t');
text(1, -0.3, 0,  'e^{j 2 \pi f t}');
text(1.1, 0, 0,  '');
text(1.1, 0, 0,  '');