Contour plot of the generalised Dirichlet distribution in S^2 {Compositional}

Contour plot of the generalised Dirichlet distribution in S^2

Description

Contour plot of the generalised Dirichlet distribution in S^2.

Usage

gendiri.contour(a, b, n = 100, x = NULL, cont.line = FALSE)

Arguments

a

A vector with three elements corresponding to the 3 (estimated) shape parameter values.

b

A vector with three elements corresponding to the 3 (estimated) scale parameter values.

n

The number of grid points to consider over which the density is calculated.

x

This is either NULL (no data) or contains a 3 column matrix with compositional data.

cont.line

Do you want the contour lines to appear? If yes, set this TRUE.

Details

The user can plot only the contour lines of a Dirichlet with a given vector of parameters, or can also add the relevant data should he/she wish to.

Value

A ternary diagram with the points and the Dirichlet contour lines.

Author(s)

Michail Tsagris and Christos Adam.

R implementation and documentation: Michail Tsagris [e-mail] and Christos Adam [e-mail].

References

Ng Kai Wang, Guo-Liang Tian and Man-Lai Tang (2011). Dirichlet and related distributions: Theory, methods and applications. John Wiley & Sons.

Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.

See Also

diri.contour, mixdiri.contour, compnorm.contour, comp.kerncontour, mix.compnorm.contour

Examples

x <- as.matrix( iris[, 1:3] )
x <- x / rowSums(x)
gendiri.contour( a = c(3, 4, 2), b = c(1, 2, 3) )