function [circumference, area] = circle(r)
% [circumference, area] = circle(r)
% Given a radius r, 
% this function returns the circumference 
% and area of a circle.
% If r is a vector, then vectors of corresponding 
% values are returned.

circumference = 2*pi*r;
area = pi*r.^2;        % .^ so we can handle vector input

% end of function circle