Contour plot of the alpha multivariate normal in S^2: Contour plot of the \(\alpha\) multivariate normal in \(S^2\)
Description
Contour plot of the \(\alpha\) multivariate normal in \(S^2\).
Usage
alfa.contour(m, s, a, n = 100, x = NULL)
Arguments
m
The mean vector of the \(\alpha\) multivariate normal model.
s
The covariance matrix of the \(\alpha\) multivariate normal model.
a
The value of a for the \(\alpha\)-transformation.
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.
Value
The contour plot of the \(\alpha\) multivariate normal appears.
Details
The \(\alpha\)-transformation is applied to the compositional data and then for a grid of points within the 2-dimensional simplex, the density of the \(\alpha\) multivariate normal is calculated and the contours are plotted.
References
Tsagris M.T., Preston S. and Wood A.T.A. (2011). A data-based power transformation for compositional data.
In Proceedings of the 4th Compositional Data Analysis Workshop, Girona, Spain.
https://arxiv.org/pdf/1106.1451.pdf