[R] triangle contour plots

[Robin Hankin]

Suppose I have three numbers p1, p2, p3 with
0 <= p1,p2,p3 <= 1  and p1+p2+p3=1,
and a  function  f=f(p1,p2,p3)   =  f(p1,p2,1-p1-p2).

How to draw a contour plot of f() on the p1+p2+p3=1 plane,
that is, an equilateral triangle?

Functions triplot(), triangle.plot(), and ternaryplot()  give
only  scatterplots, AFAICS





--
Robin Hankin
Uncertainty Analyst
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743