Compute the spatial and non-spatial Simpson index for a given multitype point pattern.
simpsonF(X, r = NULL, ...)simpson.index(X, spatial = FALSE, ...)
Multitype point pattern of class ppp (see package 'spatstat')
Vector of sizes for neighbourhoods, e.g. geometric graph with different ranges.
Further parametes for the function segregationFun.
If FALSE, return the classical aspatial index value.
If spatial, returns an fv-object, see spatstat for more information. Otherwise a numeric value.
simpson.index: The Spatial Simpson Index
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 using 4-nearest neighbours graph by default.
Rajala, Illian: A family of spatial biodiversity measures based on graphs, Env. Ecol. Stat. 2012
Shimatani, Kubota: Quantitative assesment of multispecies spatial pattern with high species diversity. Ecological Research, 19, 2004.