Re: LOGO-L> Total Turtle Trip

[Chuck Shavit <CShavit@MagicSquare.com>]

At 06:00 AM 10/28/97 -0600, Jim Muller wrote:

>Since you're getting picky one me (:>), try this one...
>
>TO CIRCLE :CENTER :RADIUS
>PU SETPOS :CENTER
>SETX XCOR - :RADIUS SETH 0 PD
>REPEAT 360 [FD (:RADIUS * 2) * PI/360 RT 1]
>PU SETPOS :CENTER PD
>END

Looks very good.

Call me picky, but I can't help making two comments:

  1. You converted a relative function a.k.a. turtle-geometry
     to absolute.  That's OK, but there is also a need for a
     function which draws a circle relative to the turtle's
     position.  In essence, if you want a circle of a given
     radius, you bring the turtle there and call that function.

  2. The RADIUS argument is not really the radius of the circle.
     The actual radius is a bit different.  It might be an 
     interesting excersize for students to explain why, and
     to debate whether the real radius is bigger or smaller
     than RADIUS.  Advanced students can correct the above
     function by adjusting the step size to account for the
     polygon approximation.

Chuck
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