function h=circle(x,y,r,c);
%
%   h=circle(x,y,r,c);
%   plots a circle of radius r at the point x,y, with style c
%   by Chuck DiMarzio, Northeastern University, December 2011
%
hold on;
theta=[0:360]*pi/180;
h=plot(r*cos(theta)+x,r*sin(theta)+y,c);
hold off;
