spatialEco (version 0.1-7)

nni: Average Nearest Neighbour Index (NNI)

Description

Calculates the NNI as a measure of clustering or dispersal

Usage

nni(x, win = "hull")

Arguments

x

An sp point object

win

Type of window 'hull' or 'extent'

Value

list object contanint NNI = nearest neighbor index, z.score = Z Score value, p = p value, expected.mean.distance = Expected meand distance, observed.mean.distance = Observed meand distance.

References

Clark, P.J., and F.C. Evans (1954) Distance to nearest neighbour as a measure of spatial relationships in populations. Ecology 35:445-453 Cressie, N (1991) Statistics for spatial data. Wiley & Sons, New York.

Examples

require(sp)
data(meuse)
  coordinates(meuse) <- ~x+y
    nni(meuse)