A versatile graphic tool

[James Hurley]

Periodically I feel the need to call attention to Turtle Graphics as  
a versatile  graphic tool in Run Rev.

There has been recent discussions on the list about drawing a graph.  
The  following script will draw a simple graph:

on mouseUp
   startTurtle --Initialize turtle graphics
   put 0,30,120,20, 40 ,22, 104, 210 into tYdata
   put 20 into dx
   drawCoorAxes
   put 0 into x
   repeat with i = 1 to the number of items in tYdata
     setxy x,item i of tYdata
     add dx to x
   end repeat
   choose the browse tool
end mouseUp

on drawCoorAxes
   forward 200
   back 200
   left 90
   forward 200
   back 200
end drawCoorAxes

With a simple change one could plot any analytic function, f(x)
As well as a vertical and horizontal mesh.
Jim Hurley