Compositional (version 5.5)

Contour plot of the skew skew-normal distribution in S^2: Contour plot of the skew skew-normal distribution in \(S^2\)

Description

Contour plot of the skew skew-normal distribution in \(S^2\).

Usage

skewnorm.contour(x, type = "alr", n = 100, appear = TRUE, cont.line = FALSE)

Arguments

x

A matrix with the compositional data. It has to be a 3 column matrix.

type

This is either "alr" or "ilr", corresponding to the additive and the isometric log-ratio transformation respectively.

n

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

appear

Should the available data appear on the ternary plot (TRUE) or not (FALSE)?

cont.line

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

Value

A ternary diagram with the points (if appear = TRUE) and the bivariate skew skew-normal contour lines.

Details

The alr or the ilr transformation is applied to the compositional data at first. Then for a grid of points within the 2-dimensional simplex the bivariate skew skew-normal density is calculated and the contours are plotted along with the points.

References

Azzalini A. and Valle A. D. (1996). The multivariate skew-skewnormal distribution. Biometrika 83(4):715-726.

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

See Also

diri.contour, mix.compnorm.contour, bivt.contour, compnorm.contour

Examples

# NOT RUN {
x <- as.matrix(iris[51:100, 1:3])
x <- x / rowSums(x)
skewnorm.contour(x)
# }