function out=drawfig3(cc,axxis)
% Like ginput, but also draws and closes the polygon.
% Two optional inputs: color/plotstyle like 'co', and
% axis, a 1x4 vector passed to the command axis -- to 
% freeze the axes at the current scaling call drawfig
% with the second argument "axis".
%
% While drawfig creates a 2xn matrix, drawfig3 creates
% a 3xn marix with ones in the third row.
%
disp('Left mouse button picks points.')
disp('Rite mouse button picks last point.')
if nargin==0
   cc='m-';
   axis([-5,5,-5,5]);
elseif nargin==1
   axis([-5,5,-5,5]);
else axis(axxis);
   end;
hold on
n=1;
[points(1,1),points(2,1),but]=ginput(1);
points(3,1)=1;
plot(points(1,1),points(2,1),cc);
while but ==1
      n=n+1
      [points(1,n),points(2,n),but]=ginput(1)
      points(3,n)=1;
      plot(points(1,n-1:n),points(2,n-1:n),cc);
      end;
%automatically close the polgon
n=n+1;
points(:,n)=points(:,1);
plot(points(1,n-1:n),points(2,n-1:n),cc);
out=points;