ellipses: Concentration ellipses (kappa-ellipses)

In biplotEZ: EZ-to-Use Biplots

Concentration ellipses (\kappa-ellipses)

Description

This function produces \kappa-ellipses, which is a useful geometrical description of the data points about the sample mean.

Usage

ellipses(bp, df=2, kappa = NULL, which = NULL,
alpha = 0.95, col = bp$sample$col[which], lty = 1, lwd = 1,
opacity = 0.25, trace = TRUE)

Arguments

bp	an object of class biplot.
df	degrees of freedom, with default 2.
kappa	value to construct \kappa-ellipse (the value of \kappa).
which	the selection of the group for ellipse construction.
alpha	size of \alpha-bag, with default 0.95.
col	colour of ellipse. Multiple \kappa-ellipse for one group will be displayed in the same colour.
lty	line type of ellipse. The same line type will be used per value of \kappa.
lwd	line width of ellipse. The same line width will be used per value of \kappa.
opacity	level of opacity, with default 0.25.
trace	logical, indicating progress of computation.

Value

A list with the following components is available:

conc.ellipses	list of coordinates for the \kappa-ellipses for each group.
col	vector of colours for the \kappa-ellipses.
lty	vector of line types for the \kappa-ellipses.
lwd	vector of line widths for the \kappa-ellipses.
alpha	vector of \alpha values.

References

Gower, J., Gardner-Lubbe, S. & Le Roux, N. (2011, ISBN: 978-0-470-01255-0) Understanding Biplots. Chichester, England: John Wiley & Sons Ltd.

Examples

biplot (iris[,1:4]) |> PCA(group.aes=iris[,5]) |> ellipses(kappa=2) |> plot()

biplotEZ documentation built on April 4, 2025, 2:20 a.m.