sperich (version 1.3-7)

searchClusters: Search clusters in the result grid of species richness estimation.

Description

This routine searches clusters in the result grid of species richness estimation.

Usage

searchClusters(species.richness, dimension, shift, resolution, clusterlimit)

Arguments

species.richness

The grid that should be adjusted. It contains the result of species richness estimation or cross-validation.

dimension

The dimension of the processed grid.

shift

The geographic coordinates of the origin of the grid.

resolution

The resolution of the grid in (geographical) degree.

clusterlimit

The limit under which values of 'species.richness' should not be used to build clusters.

Value

• This function returns a list containing vectors of the position of pixels which belong together.

Details

This routine searches clusters in the result grid of species richness estimation to find centers of species richness.

References

Raedig, C., Dorman, C.F., Hildebrandt, A. and Lautenbach, S. (2010). Reassessing Neotropical angiosperm distribution patterns based on monographic data: a geometric interpolation approach. Biodivers Conserv, 19, 1523-1546.

Examples

##load data
data(dataset.all.species)
data(dataset.landwater)

##create grid parameters
dimension <- getDimension(dataset.all.species, resolution=1)
shift <- getShift(dataset.all.species)

##create landwatermask
landwatermask.nocoast <- createLandwatermask(dataset.landwater, 
					dimension, shift, resolution=1)

##estimate species richness
species.richness.weighted <- species.richness(dataset.all.species,
landwatermask.nocoast, distances=1:10, weight=0.5, dimension,
shift, resolution=1, upperbound=3000, all.species=1:20)

##prepare clustersearch
clusterlimit <- 100

##adjust species richness
clusterlist <- searchClusters(species.richness.weighted, 
		dimension, shift, resolution=1, clusterlimit)