spatialsegregation-simpson {spatialsegregation}R Documentation

Spatial Simpson Index

Description

Compute the spatial and aspatial Simpson index for a given multitype point pattern.

Usage

simpsonF<-function(X, r=NULL, ...)
simpson.index(X, spatial=FALSE, ...)

Arguments

X Multitype point pattern of class ppp (see package 'spatstat')
r Vector of sizes for neighbourhoods, e.g. geometric graph with different ranges.
spatial If FALSE, return the classical aspatial index value.
... Further parametes for the function segregationFun.

Details

Date: 2009-03-09
License: GPL v2 or later

The form of Simpson index is S = 1 - sum pi_tau, where the sum is over the types of the pattern, and pi_tau is like in Shimatani& Kubota 2004.

The function simpsonF is the main calculation function. Uses function segregationFun.

The function simpson.index is a shortcut to get a single value for the pattern. Uses 4-nn graph by default.

Value

Returns an fv-object, see spatstat for more information.

Author(s)

Tuomas Rajala University of Jyvaskyla, Finland tuomas.a.rajala@jyu.fi

References

Rajala, Illian: Graph-based description of mingling and segregation in multitype spatial point patterns. To appear 2009.

Shimatani, Kubota: Quantitative assesment of multispecies spatial pattern with high species diversity. Ecological Research, 19, 2004.


[Package spatialsegregation version 2.11 Index]