Matlab Simulation: Point (symbol) Moving from start point to end point and back

Question

I would like to create an animation to demonstrate LDPC coding which is based on Sum-Product Algorithm

So far I have created a graph which shows the connections betw

Answer 1

From the documentation for comet.m

t = 0:.01:2*pi;
x = cos(2*t).*(cos(t).^2);
y = sin(2*t).*(sin(t).^2);
comet(x,y);