MIA, Ask an Expert: Simplest oval procedure... From Sergei in Moscow

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from: Alain <alain@xxxxxxx>
date: Fri Mar  9 05:13:57 2007
platform: Platform not specified
version: MicroWorlds Ex

Simplest oval procedure... From Sergei in Moscow:

Use 2 turtles. First one (t1) draw the usual circle, second one 
(t2) is "watching" t1: it's x-coordinate is the same as t1's 
and it's y-coordinate is (for example) half of t1's:

setpos list ask "t1 [xcor] 0.5 * ask "t1 [ycor].

The procedures go like this:

to oval
t1, home pu
t2, home pd
repeat 360 [followme]
end

to followme
t1, fd 1 rt 1
t2, setpos list ask "t1 [xcor] 0.5 * ask "t1 [ycor]
end