ksupp: Kernel support estimate

Description

Kernel support estimate for 2 and 3-dimensional data.

Usage

ksupp(fhat, cont=95, abs.cont, convex.hull=TRUE)
# S3 method for ksupp
plot(x, display="plot3D", ...)

Value

A kernel support estimate is an object of class ksupp, i.e. a 2- or 3-column matrix which delimits the (convex hull of the) level set of the density estimate fhat.

Arguments

fhat: object of class kde
cont: percentage for contour level curve. Default is 95.
abs.cont: absolute density estimate height for contour level curve
convex.hull: flag to compute convex hull of contour level curve. Default is TRUE.
x: object of class ksupp
display: one of "plot3D", "rgl" (required for 3-d only)
...: other graphics parameters

Details

The kernel support estimate is the level set of the density estimate that exceeds the cont percent contour level. If this level set is a simply connected region, then this can suffice to be a conservative estimate of the density support. Otherwise, the convex hull of the level set is advised. For 2-d data, the convex hull is computed by chull; for 3-d data, it is computed by geometry::convhulln.

Examples

Run this code

data(grevillea)
fhat <- kde(x=grevillea)
fhat.supp <- ksupp(fhat)
plot(fhat, display="filled.contour", cont=seq(10,90,by=10))
plot(fhat, cont=95, add=TRUE, col=1)
plot(fhat.supp, lty=2)

data(iris)
fhat <- kde(x=iris[,1:3])
fhat.supp <- ksupp(fhat)
plot(fhat)
plot(fhat.supp, add=TRUE, col=3, alpha=0.1)