avg_nn_dist: Compute average nearest neighbor distance

In MoBiodiv/mobr: Measurement of Biodiversity

Compute average nearest neighbor distance

Description

This function computes the average distance of the next nearest sample for a given set of coordinates. This method of sampling is used by the function rarefaction when building the spatial, sample-based rarefaction curves (sSBR).

Usage

avg_nn_dist(coords)

Arguments

coords

a matrix with n-dimensional coordinates

Value

a vector of average distances for each sequential number of accumulated nearest samples.

Examples

# transect spatial arrangement
transect = 1:100
avg_nn_dist(transect)
grid = expand.grid(1:10, 1:10)
avg_nn_dist(grid)
oldpar <- par(no.readonly = TRUE)
par(mfrow=c(1,2)) 
plot(avg_nn_dist(transect), type='o', main='transect',
     xlab='# of samples', ylab='average distance')
# 2-D grid spatial arrangement
plot(avg_nn_dist(grid), type='o', main='grid',
     xlab='# of samples', ylab='average distance')
par(oldpar)

MoBiodiv/mobr documentation built on Oct. 26, 2024, 10:51 a.m.