How can I plot locus of a rotating phasor with time?

Hello! I want to plot the trajectory of a rotating vector of continuously changing magnitude. Please help me!!

Answer 1

[Shunichi Kusano]

This is a simple example. Plase change "A" and "theta" to what you like.

t = 0:0.01:10; % time
A = t.^2; % amplitude changing with time
theta = 2*pi*t; % phase (rotating)
plot(A.*cos(theta), A.*sin(theta), 'r.-'); % trajectory

hope this helps.