Re: LOGO-L> Total Turtle Trip

[George Mills <mills@softronix.com>]

It is different, because Chuck's (similar to ARC) method has
each point at least exactly (at much as floating point allows) on
the true circle.

Where as the method you describe below only your first point is
actually on the circle.

Try chucks method with only 4 points and your method with 4
points and then draw a "true" circle with ARC.

The 2 methods do approach each other as you go to infinity
but Chucks method has a nice property that each point is on
the circle no matter how many points.

However Chuck has not admitted ARC does the same thing.
But I know it is because I know how his Logo code would get executed
and ARC simply cuts out some unnecessary work. :-)

Jim Muller wrote:
> 
> >  * If you want your students to use the computer to visualize the
> >definition of a circle (all the points that are equidistant from a given
> >center), you don't have to use a polygon.  Another way would be to write a
> >simple program that draws dots around a center: each step would go forward
> >with the pen up, draw a dot, go back, and turn.  As the number of dots
> >increases, the collection looks more and more like a circle.  When the dots
> >are denser than the size of a pixel, you get a perfect circle -- or as
> >perfect as you can get on a computer screen.
> >
> >
> 
> Chuck ==>
> 
> Here's a procedure that does just what you stated above. Other than some
> added steps, how does this differ from the polygon procedure? It's still FD
> 1, RT 1 repeated for as many times as required to draw a line equidistant
> from a center.
> 
> TO CIRCLE :SIDE
> HOME CS PU
> REPEAT 360 [FD :SIDE POINT BK :SIDE RT 1]
> END
> 
> TO INFO
> ; CHAPTER 7 POLYGONS, CIRCLES, STARS, AND STUFF
> ; HOW DO YOU DRAW A  CIRCLE THAT FITS THE CLASSIC
> ; DEFINITION OF A CIRCLE: A CURVED LINE WHERE ALL POINTS
> ; ON THE LINE ARE THE SAME DISTANCE FROM A CENTRAL POINT.
> ; TYPE CIRCLE AND A RADIUS TO SEE.
> ;;
> PR [SEE THE INFO PROCEDURE FOR MORE INFORMATION.]
> END
> 
> TO POINT
> PD RT 90 FD 1
> BK 1 LT 90 PU
> END
> 
> Make "startup [INFO]
> 
> Regards...Jim
> 
> >+>+>+>+>+>+>+>+>+>+>+>+>+>+>+>
> Jim Muller
> jmul@cyberramp.net
> The Great Logo Adventure at
> http://www.cyberramp.net/~jmul
> >+>+>+>+>+>+>+>+>+>+>+>+>+>+>+>
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-- 
===============================================================
George Mills (mills@softronix.com)
http://www.softronix.com/
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