inahull {alphahull} | R Documentation |
This function determines for one or more points p
whether they belong to the \alpha
-convex hull of a sample.
inahull(ahull.obj, p)
ahull.obj |
Object of class |
p |
Numeric vector with two components describing a point in the plane or two-column matrix of points. |
The complement of the \alpha
-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.
in.ahull |
A logical vector specifying whether each point in |
## 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)