simpsonF: Spatial Simpson index

In antiphon/spatialsegregation: Segregation Measures for Multitype Spatial Point Patterns

Description

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

Usage

simpsonF(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.
...	Further parametes for the function segregationFun.
spatial	If FALSE, return the classical aspatial index value.

Details

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.

Value

If spatial, returns an fv-object, see spatstat for more information. Otherwise a numeric value.

Functions

• simpson.index: The Spatial Simpson Index

References

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.

antiphon/spatialsegregation documentation built on Nov. 21, 2020, 10:39 p.m.