Nearest neighbour distances
Computes the distance from each point to its nearest neighbour in a point pattern.
nndist(x, y=NULL, method="C")
- Arguments specifying the $x$ and $y$ coordinates of
a set of points. Typically
ywould be numeric vectors of equal length. Alternatively
ymay be omitted and
xmay be a point patter
- String specifying which method of calculation to use.
This function computes the Euclidean distance from each point in a point pattern to its nearest neighbour (the nearest other point of the pattern).
method = "interpreted" then the distances are
computed using interpreted R code only. If
then C code is used. The C code is faster by two to three orders of magnitude
and uses much less memory.
If there is only one point (if
x has length 1),
then a nearest neighbour distance of
Inf is returned.
If there are no points (if
x has length zero)
a numeric vector of length zero is returned.
- Numeric vector of the nearest neighbour distances for each point.
An infinite value is returned if there is only one point in the point pattern.
x <- runif(100) y <- runif(100) d <- nndist(x, y) data(cells) d <- nndist(cells)