Tval {nnspat} | R Documentation |
T
value in NN structure
Description
Returns the T
value,
which is the number of triplets (z_i, z_j, z_k)
with
"NN(z_i) = NN(z_j) = z_k
and NN(z_k) = z_j
"
where NN(\cdot)
is the nearest neighbor function.
Note that in the NN digraph,
T+R
is the sum of the indegrees of the points in the reflexive pairs.
This quantity (together with Q
and R
) is used in
computing the variances and covariances of the entries of the
reflexivity contingency table.
See (Ceyhan and Bahadir (2017))
for further details.
Usage
Tval(W, R)
Arguments
W |
The incidence matrix, |
R |
The number of reflexive NNs (i.e., twice the number of reflexive NN pairs) |
Value
Returns the T
value.
See the description above for the details of this quantity.
Author(s)
Elvan Ceyhan
See Also
Qval
, Qvec
, sharedNN
,
and Rval
Examples
#3D data points
n<-10
Y<-matrix(runif(3*n),ncol=3)
ipd<-ipd.mat(Y)
W<-Wmat(ipd)
R<-Rval(W)
Tval(W,R)
#1D data points
X<-as.matrix(runif(15)) # need to be entered as a matrix with one column
#(i.e., a column vector), hence X<-runif(5) would not work
ipd<-ipd.mat(X)
W<-Wmat(ipd)
R<-Rval(W)
Tval(W,R)
#with ties=TRUE in the data
Y<-matrix(round(runif(30)*10),ncol=3)
ipd<-ipd.mat(Y)
W<-Wmat(ipd,ties=TRUE)
R<-Rval(W)
Tval(W,R)
[Package nnspat version 0.1.2 Index]