Plotting random signal on circle

Question

I have some random signal (for example sin signal) with the time scale.

t=0:0.1:2*pi
y=sin(t)
plot(t,y)

Now I want to draw this signal on this circle. So the time vector actually becomes an envelope of the circle. Envelope of the circle represents "y = 0" in cartesian coordinate system.

Here is an example of what I expect the output to look like:

_{(source: slikomat.com)}

Thank in advanced!

Answer 1

You need to add "noise" to the radius of the circle, roughly around r=1:

th = linspace( 0, 2*pi, N ); %// N samples
noise = rand( 1, N ) * .1; %// random noise in range [0..0.1]
r = 1+noise; %// add noise to r=1
figure;
plot( r.*cos(th), r.*sin(th) ); title('noise on circle');

An example plot would look like: