[R] drawing ellipses in R

Barry Rowlingson b.rowlingson at lancaster.ac.uk
Tue Nov 1 09:44:04 CET 2011

On Tue, Nov 1, 2011 at 4:49 AM,  <mmstat at comcast.net> wrote:
> Hello,
> I have been following the thread dated Monday, October 9, 2006 when Kamila Naxerova asked a question about plotting elliptical shapes. Can you explain the equations for X and Y. I believe they used the parametric form of x and y (x=r cos(theta), y=r sin(theta). I don't know what r is here ? Can you explain 1)the origin of these equations and 2) what is r?

 The origin of these equations? Probably this guy:

 Or maybe Euclid.

 What is r (as opposed to R)? Mathematical questions are nicely
answered by Mathworld:


 - a fantastic resource for maths and stats information.


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