Contour plot of the kernel density estimate in S^2: Contour plot of the kernel density estimate in \(S^2\)
Description
Contour plot of the kernel density estimate in \(S^2\).
Usage
comp.kerncontour(x, type = "alr", n = 50, 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.
cont.line
Do you want the contour lines to appear? If yes, set this TRUE.
Value
A ternary diagram with the points and the kernel contour lines.
Details
The alr or the ilr transformation are applied to the compositional data. Then, the optimal bandwidth using maximum
likelihood cross-validation is chosen. The multivariate normal kernel density is calculated for a grid of points.
Those points are the points on the 2-dimensional simplex. Finally the contours are plotted.
References
M.P. Wand and M.C. Jones (1995). Kernel smoothing, CrC Press.
Aitchison J. (1986). The statistical analysis of compositional data. Chapman & Hall.