[R] circle / oval / semicircle ?

[ivo welch]

thanks, guys.  circles might be a good candidate for a graphics 
primitive in the next R version, if only because---unlike the solutions 
here---I believe that postscript/pdf have scaleable primitives---though 
I am no postscript expert.  of course, if I knew what I was talking 
about, I would just write the function and submit it.  the closest I 
have found was in http://wtonline.vitalnews.com/Pages/Tip0163.html

regards, /ivo