draw

 DRAW Draws points on the current plot, returning their locations.
         If n, the number of points is not given, DRAW stops drawing 
         when you hit right button on mouse

      Usage:   [x,y]=draw(n);
            n = points to draw
            x = returned x locations drawn points
            y = returned y locations drawn points

0001 function [x,y]=draw(n);
0002 % DRAW Draws points on the current plot, returning their locations.
0003 %         If n, the number of points is not given, DRAW stops drawing
0004 %         when you hit right button on mouse
0005 %
0006 %      Usage:   [x,y]=draw(n);
0007 %            n = points to draw
0008 %            x = returned x locations drawn points
0009 %            y = returned y locations drawn points
0010 %
0011 if nargin==0
0012       n=2000;
0013 end              
0014 disp('Click left button to draw, right button to quit')
0015 i=1;
0016 [x(1,1),x(1,2),ibutton]=ginput(1);
0017 line(x(1,1),x(1,2),'color','cyan','Marker','o');
0018 while (i<n)&(ibutton==1) 
0019   i=i+1;
0020   [xx,yy,ibutton]=ginput(1);
0021   if(ibutton==1),
0022    x(i,1)=xx;
0023    x(i,2)=yy;
0024    line(x( (i-1):i,1),x((i-1):i,2), 'color','cyan','Marker','o');
0025    line(x(i,1),x(i,2), 'color','cyan','Marker','o');
0026   end
0027 end
0028 if nargout==2
0029   y=x(:,2);
0030   x=x(:,1);
0031 end
0032 
0033