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Points on Convex Hull

Source: R/chull.R
is_chull.Rd

Given a set of locations, this function determines which locations belongs to the convex hull (or envelope) of the set.

Usage

is_chull(x, y)

isChull(x, y)

Arguments

x

A vector of x (or longitude) coordinates.

y

A vector of y (or latitude) coordinates.

Value

A numerical vector of the same length as x and y.

0 indicates that the corresponding location is not part of the convex hull of the set. Values >0 indicates that the corresponding location is part of the convex hull, and each value corresponds to the order of the locations along the convex hull polygon.

See also

chull_area, chull_perimeter

Author

Simon Garnier, garnier@njit.edu

Examples

x <- rnorm(25)
y <- rnorm(25, sd = 3)
is_chull(x, y)
#>  [1] 0 0 0 1 6 0 0 0 0 0 0 0 0 2 0 0 0 4 0 7 0 0 5 0 3