spatialsegregation-ISAR {spatialsegregation}R Documentation

Individual Species Area Relationship

Description

Compute the Individual Species Area Relationship ( ISAR ) for a given multitype point pattern.

Usage

isarF(pp, parvec = 1:20, graph_type = "knn", type = NULL, ...)
isar_index(pp, graph_type = "knn", graph_par = 4, type = NULL, ...)

Arguments

pp Multitype point pattern (see package 'spatstat')
parvec Default 1:20. Vector for the neighbourhood defining graph, e.g. geometric graph with different r.
graph_type Default knn. Type of the neighbourhood graph. Accepts: knn, geometric, delauney, gabriel.
type Default NULL. Calculate only for type 'type'. If NULL compute mean over all types.
graph_par The single parameter to calculate the value in.
... Further tuning parametes for the function segregationFun.

Details

Date: 2009-03-04
License: GPL v2 or later

Extension of ISAR-function introduced in WGGH 2007. In effect calculates the expected amount of different types present in the neighbourhood of a typical point.

The function isarF is the main calculation function. Uses function 'segregationFun' with parameter ftype=4.

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

Author(s)

Tuomas Rajala University of Jyvaskyla, Finland tarajala@maths.jyu.fi

References

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

Wiegand, Gunatilleke, Gunatilleke, Huth: How individual species structure diversity in tropical forests. PNAS, nov 16, 2007.


[Package spatialsegregation version 1.93 Index]