Ternary or Triangular Plots

PlotTernary plots in a triangle the values of three variables. Useful for mixtures (chemistry etc.).

PlotTernary(x, y = NULL, z = NULL, args.grid = NULL, lbl = NULL, main = "",...)

Arguments

x

vector of first variable. Will be placed on top of the triangle.

y

vector of second variable (the right corner).

z

vector of third variable (on the left corner).

args.grid

list of additional arguments for the grid. Set this argument to NA if no grid should be drawn. The usual color and linetype will be used.

main

overall title for the plot.

lbl

the labels for the corner points. Default to the names of x, y, z.

...

the dots are sent to points

References

J. Aitchison (1986) The Statistical Analysis of Compositional Data. Chapman and Hall, p.360.

Venables, W. N. and Ripley, B. D. (2002) Modern Applied Statistics with S. Fourth edition. Springer.

See also

example in Skye

Author

Andri Signorell <andri@signorell.net> based on example code by W. N. Venables and B. D. Ripley mentioned

Examples

# some random data in three variables
c1 <- runif(25)
c2 <- runif(25)
c3 <- runif(25)

# basic plot
par(mfrow=c(1, 2))
PlotTernary(c1, c2, c3, args.grid=NA)
#> Warning: row(s) of X will be rescaled

if (FALSE) { # \dontrun{
# plot with different symbols and a grid using a dataset from MASS
data(Skye, package="MASS")

PlotTernary(Skye[c(1,3,2)], pch=15, col=DescTools::hred, main="Skye",
            lbl=c("A Sodium", "F Iron", "M Magnesium"))
} # }