Elliptical orbits for planets

[mwforum@xxxxxxxxxxxxxxxxxx (Daniel Ajoy)]

Wow, it looks like an ellipse to me, are you sure it is
an oval? Do you understand know how it works? Could you
please explain it's rationale.

I have tried and tried for some time to do one, and 
failed, here is one of my attempts:

to ellipse2
make "n 0
repeat 36 [
 fd 10
 rt 360 / 162 * abs (abs :n - 17.5) - 9
 make "n :n + 1
]
end


And to the original poster, when I was young I tried
to make astronomically correct planet-paths but you
should see how much the true eccentricity factors 
of the ellipses affect the circularity the the paths. 
It almost can't be noticed. If the true paths were
very flat (like in teachers' drawings) humans wouldn't 
survive it.



On 4 Mar 2003 at 21:54, Walter Smith wrote:

> This is how I had my students make ovals . Walt
> 
> to ellipse :s :e
> pd
> local "n 
> make "n 0
> repeat 360[rt :n fd :s lt :n lt :n fd :s * :e rt :n make "n :n + 1]
> end
> 
>  
> 
> -----Original Message-----
> From: mwforum-admin@xxxxxxxxxxxxxxxxxx
> [mailto:mwforum-admin@xxxxxxxxxxxxxxxxxx] On Behalf Of
> GrahamWilliams@xxxxxxxxxxxxxxxxxxxxxx
> Sent: Tuesday, March 04, 2003 9:32 PM
> To: mwforum@xxxxxxxxxxxxxxxxxx
> Subject: [MWForum]Elliptical orbits for planets
> 
>  
> 
> Some of my Year 6 students are trying to create a solar-system project .They
> have commented that similar projects on the web have the planets moving in
> circular orbits but my students want to be as astronomically-correct as
> possible and use more elliptical orbits . The problem is that I don't know a
> 'formula' to get turtle to move in an elliptical-type path. I'd very much
> appreciate any assistance from cyberspace.  Thanks  Graham Williams
> Victoria  Australia
> 
>