function [x,y]=circlefn(r);
%CIRCLE-A script file to draw a unit circle.
%File written by Dorothy Merritts. Last modified 1/4/2000
%-----------------------
%Call syntax: [x,y]=circlefn(r);
%Input: r=specified radius
%Output: [x,y]=the x- and y-coordinates of data points
r=input('Enter the radius of the circle:  ')
theta=linspace(0,2*pi,100); 	%create vector theta
x=r*cos(theta);					%generate x-coordinates
y=r*sin(theta);					%generate y-coordinates
plot(x,y,0,0,'+');				%plot the circle
axis('equal');					%set equal scale on axes
title(['Circle of radius r =',num2str(r)])	%put a title with the value of r
