spatialsegregation-simpson {spatialsegregation} | R Documentation |
Compute the spatial and aspatial Simpson index for a given multitype point pattern.
simpsonF<-function(X, r=NULL, ...) simpson.index(X, spatial=FALSE, ...)
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 . |
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.
Returns an fv
-object, see spatstat
for more information.
Tuomas Rajala University of Jyvaskyla, Finland tuomas.a.rajala@jyu.fi
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.