| seg.ind {nnspat} | R Documentation |
Dixon's Segregation Indices for NNCTs
Description
Returns Dixon's segregation indices in matrix form based on
entries of the NNCT, ct.
Segregation index for cell i,j is defined as
log(N_{ii}(n-n_i)/((n_i-N_{ii})(n_i-1)) if i=j
and
as log(N_{ij}(n-n_j-1)/((n_i-N_{ij})(n_j))
if i \ne j.
See (Dixon (2002); Ceyhan (2014)).
The argument inf.corr is a logical argument
(default=FALSE) to avoid \pm \infty
for the segregation indices.
If TRUE indices are modified so that
they are finite and if FALSE the above definition is used.
(See Ceyhan (2014) for more detail).
Usage
seg.ind(ct, inf.corr = FALSE)
Arguments
ct |
A contingency table, in particular an NNCT |
inf.corr |
A logical argument (default= |
Value
Returns a matrix of segregation indices
which is of the same dimension as ct.
Author(s)
Elvan Ceyhan
See Also
Pseg.coeff, seg.coeff,
Zseg.ind, and Zseg.ind.ct
Examples
n<-20 #or try sample(1:20,1)
Y<-matrix(runif(3*n),ncol=3)
ipd<-ipd.mat(Y)
cls<-sample(1:2,n,replace = TRUE) #or try cls<-rep(1:2,c(10,10))
ct<-nnct(ipd,cls)
ct
seg.ind(ct)
seg.ind(ct,inf.corr = TRUE)
#cls as a factor
na<-floor(n/2); nb<-n-na
fcls<-rep(c("a","b"),c(na,nb))
ct<-nnct(ipd,fcls)
seg.ind(ct)
#############
n<-40
Y<-matrix(runif(3*n),ncol=3)
ipd<-ipd.mat(Y)
cls<-sample(1:4,n,replace = TRUE) #or try cls<-rep(1:2,c(10,10))
ct<-nnct(ipd,cls)
seg.ind(ct)
seg.ind(ct,inf.corr = TRUE)
ct<-matrix(c(0,10,5,5),ncol=2)
seg.ind(ct)
seg.ind(ct,inf.corr = TRUE)