inahull: Determines for one or more points whether they belong to the...

In alphahull: Generalization of the Convex Hull of a Sample of Points in the Plane

Determines for one or more points whether they belong to the alpha-convex hull

Description

This function determines for one or more points p whether they belong to the α-convex hull of a sample.

Usage

inahull(ahull.obj, p)

Arguments

ahull.obj	Object of class "ahull" returned by the funcion ahull.
p	Numeric vector with two components describing a point in the plane or two-column matrix of points.

Details

The complement of the α-convex hull of a sample is calculated by complement. The function inahull checks whether each point in p belongs to any of the open balls or halfplanes that define the complement.

Value

in.ahull

A logical vector specifying whether each point in p belongs to the α-convex hull.

See Also

ahull, complement.

Examples

## Not run: 
# Random sample in the unit square
x <- matrix(runif(100), nc = 2)
# Value of alpha
alpha <- 0.2
# alpha-convex hull
ahull.obj <- ahull(x, alpha = alpha)
# Check if the point (0.5, 0.5) belongs to the alpha-convex hull
inahull(ahull.obj, p = c(0.5, 0.5))
# Check if the points (0.5, 0.5) and (2, 2) belong to the alpha-convex hull
inahull(ahull.obj, p = rbind(c(0.5, 0.5), c(2, 2)))

## End(Not run)

alphahull documentation built on June 16, 2022, 5:10 p.m.