[R-sig-eco] Plotting ternary diagrams

[Phil Novack-Gottshall]

Hi all,

Can anyone point me to a function for plotting a ternary diagram (a 
triangular plot; typically, each axis ranges 0-100% with cumulative 
value for each point adding to 100% along all three axes)?  It's 
frequently used by geologists to plot sedimentological or 
mineralogical composition, and I think I've seen it used in biome 
mapping (temperature/elevation/moisture).

A bit further afield, do any functions exist to extend this to 4 
axes, as a pyramidal quarternary diagram?

Thanks for any advice,
Phil


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   Phil 
Novack-Gottshall                        pnovackg at westga.edu 


   Assistant Professor
   Department of Geosciences
   University of West Georgia
   Carrollton, GA 30118-3100
   Phone: 678-839-4061
   Fax: 678-839-4071
   http://www.westga.edu/~pnovackg
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~