[R] Placing a Shaded Box on a Plot

[Ken]

Stephanie Cooke <cooke.stephanie <at> gmail.com> writes:

> 
> Hello,
> 
> I would like to place shaded boxes on different areas of a
> phylogenetic tree plot. Since I can not determine how to find axes on
> the phylogenetic tree plot I am not able to place the box over certain
> areas. Below is example code for the shaded box that I have tried to
> use, and the first four values specify the position.
> 
> rect(110, 400, 135, 450, col="grey", border="transparent")
> 
> Any suggestions on how to place a shaded box to highlight certain
> areas of a plot I would greatly appreciate.
> 
> 

Stephanie,
See ?polygon() or maybe ?segments(). I'm not familar with phylogenetic tree
plots, so this might not work.  You might have to play around with different
values until you find the range of the axes.  Good luck.