clf %clear plot
clear x y  %clear vars x y
plot(0,0),axis([-2,2,-2,2]),hold on 
[x(1),y(1)]=ginput(1), plot(x(1),y(1),'*')  %input and plot 1. point
[x(2),y(2)]=ginput(1), plot(x(2),y(2),'*')  % ditto for 2.  point
plot([x(1),x(2)],[y(1),y(2)]) % connect both with line