[R] Ternary or Triangular Plots (soil texture triangle plot)?

[Dan Bolser]

Hi,

I am trying to create a triangular plot to show the 'composition' of a 
set of items with three variables (historically the percent sand, silt 
and clay in soil).

So far I have tried the 'soil texture triangle plot' in the package 
plotrix and the 'ternary or triangular plots' in the package cwhtool 
(cwhmisc). Both have strengths and weaknesses, but neither has a 
'standard' or 'generic'  feel about it.

To save myself time I would like to ask the list if there is a preferred 
or standard implementation of the triangle plot that will let me,

* Label the three axes
* Specify a range for the three axis
* Label each point with a string
* Add lines perpendicular to each axis

Or in general if there is an implementation of the triangle plot which 
supports the standard plotting options.

Thanks very much for any pointers,

Dan.