[R] Draw a circle on a filled.contour() plot

[Webmaster]

> The output produced by 'filled.contour' is actually a combination
>      of two plots; one is the filled contour and one is the legend.
>      Two separate coordinate systems are set up for these two plots,
>      but they are only used internally - once the function has  
> returned
>      these coordinate systems are lost.  If you want to annotate the
>      main contour plot, for example to add points, you can specify
>      graphics commands in the 'plot.axes' argument.  An example is
>      given below.

Thanks!

I now have another question (hopefully the last) for which I couldn't  
find an answer in the mailing-list archives: how can I get rid of the  
color key on the contour.filled() plot? I that question, unanswered,  
in a post one year ago on this same list, so I hope it's by any mean  
possible... (I think it's possible to change the code completely and  
use image(), but it's much less pretty).

FX