# nndist

0th

Percentile

##### Nearest neighbour distances

Computes the distance from each point to its nearest neighbour in a point pattern.

Keywords
spatial
##### Usage
nndist(x, y=NULL, method="C")
##### Arguments
x,y
Arguments specifying the $x$ and $y$ coordinates of a set of points. Typically x and y would be numeric vectors of equal length. Alternatively y may be omitted and x may be a point patter
method
String specifying which method of calculation to use. Values are "C" and "interpreted".
##### Details

This function computes the Euclidean distance from each point in a point pattern to its nearest neighbour (the nearest other point of the pattern).

If method = "interpreted" then the distances are computed using interpreted R code only. If method="C" 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.

##### Value

• Numeric vector of the nearest neighbour distances for each point.

##### Warnings

An infinite value is returned if there is only one point in the point pattern.