clc; clear all ;
N = 20 ;
x = linspace(0,1,N) ;
y = linspace(0,1,N) ;
[X,Y] = meshgrid(x,y) ;
% pick boundaries
x = [X(1,:)' ; X(:,end) ; flipud(X(end,:)') ;flipud(X(:,1))] ;
y = [Y(1,:)' ; Y(:,end) ; flipud(Y(end,:)') ;flipud(Y(:,1))] ;
% x(end) = [] ;y(end) = [] ;
% circle
th = linspace(0,2*pi) ;
r = 0.1 ;
for i = 1:length(x)
xc = x(i)+r*cos(th) ;
yc = y(i)+r*sin(th) ;
plot(x,y,'.-r') ;
hold on
plot(xc,yc,'b');
hold off
% if condition % put your condition to stop the circle
pause(0.1)
% end
end
