Plotting a circle always around a moving point

I need to plot a circle whose center is a moving point. The point is moving with its path being plotted using "animatedline". However, I want to show only the current circle centering the point at a particular instant and the previous circles are to be cleared. Please help.

Answer 1

[KSSV]

x = linspace(0,2*pi) ;
y = cos(x) ;
R = 0.1 ;
for i = 1:length(x)
    plot(x(1:i),y(1:i))    
    
    axis([0 6 -2 2])
    hold on
    xc = x(i)+R*cos(x) ; 
    yc = y(i)+sin(x) ; 
    plot(xc,yc,'r')
    hold off
    drawnow
    pause(0.1)
end

Read about comet.

[Rudrashis Majumder]

Thanks a lot...

Answer 2

[Jos (10584)]

Adapted from the help of animatedline:

numpoints = 10000; 
x = linspace(0,4*pi,numpoints); 
y = sin(x); 
pc = [-.1 -.1 .2 .2] ; % position of circle
figure 
h = animatedline;
hc = rectangle('Position', [x(1) y(1) 0 0]+pc,'Curvature',1, 'FaceColor','r') ; % draw circle
axis([-pi,5*pi,-1.5,1.5]) 
for k = 1:numpoints 
    addpoints(h,x(k),y(k)) 
    set(hc,'Position', [x(k) y(k) 0 0] + pc) ; % adjust position of circle
    drawnow update 
end 

[Rudrashis Majumder]

Thank you very much.