var.seg.coeff {nnspat}

Variances of Segregation Coefficients in a Multi-class Case

Description

Returns the variances of segregation coefficients in a multi-class case based on the NNCT, ct in a vector of length k(k+1)/2, the order of the variances are as in the order of rows output of ind.seg.coeff(k). These variances are valid under RL or conditional on Q and R under CSR.

See also (Ceyhan (2014)).

The argument covN is the covariance matrix of N_{ij} (concatenated rowwise).

Usage

var.seg.coeff(ct, covN)

Arguments

ct

A nearest neighbor contingency table

covN

The k^2 \times k^2 covariance matrix of row-wise vectorized entries of NNCT

Value

A vector of length k(k+1)/2, whose entries are the variances of segregation coefficients for the entry i,j in the NNCT, where the order of the variances are as in the order of rows output of ind.seg.coeff(k).

Author(s)

Elvan Ceyhan

References

Ceyhan E (2014). “Segregation indices for disease clustering.” Statistics in Medicine, 33(10), 1662-1684.

See Also

seg.coeff, cov.seg.coeff, var.nnsym and var.nnct and

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)

W<-Wmat(ipd)
Qv<-Qvec(W)$q
Rv<-Rval(W)
varN<-var.nnct(ct,Qv,Rv)
covN<-cov.nnct(ct,varN,Qv,Rv)

var.seg.coeff(ct,covN)
varPseg.coeff(ct,covN)

#cls as a factor
na<-floor(n/2); nb<-n-na
fcls<-rep(c("a","b"),c(na,nb))
ct<-nnct(ipd,fcls)

var.seg.coeff(ct,covN)

#############
n<-40
Y<-matrix(runif(3*n),ncol=3)
cls<-sample(1:4,n,replace = TRUE)  #or try cls<-rep(1:2,c(10,10))
ipd<-ipd.mat(Y)
ct<-nnct(ipd,cls)

W<-Wmat(ipd)
Qv<-Qvec(W)$q
Rv<-Rval(W)
varN<-var.nnct(ct,Qv,Rv)
covN<-cov.nnct(ct,varN,Qv,Rv)

var.seg.coeff(ct,covN)