how do I make dots move within a circle?

How do I make certain dots move within a circle? While other dots move outside the circle?

[KSSV]

How the dots are? How dots are distributed?

[TADA]

do you mean as an animation?

[TADA]

something like that maybe?

% radii
r = 1;
rInner = r - 0.1;
rOuter = r + 0.1;

% theta
t = linspace(0, 2*pi);

% animation settings
frameshift = 0.05;
fps = 24;
frameInterval = 1/fps;
numFrames = 500;

% circle data
x = r*cos(t);
y = r*sin(t);

% animation loop
for i = 1:numFrames
    % plot the circle
    plot(x,y);
    axis equal;
    hold on;
    
    % calculate the inner/outer dots positions
    xout = (rOuter)*cos(t + i * frameshift);
    yout = (rOuter)*sin(t + i * frameshift);
    xin = (rInner)*cos(t - i * frameshift);
    yin = (rInner)*sin(t - i * frameshift);
    
    % plot inner/outer dots
    plot(xout, yout, '.');
    plot(xin, yin, '.');
    
    % pause until next frame
    pause(frameInterval);
    
    % to clear the plot next iteration
    hold off;
end

[Walter Roberson]

comet()