R: Provide information about a hierarchical clustering
cluinf
R Documentation
Provide information about a hierarchical clustering
Description
Agglomerative hierarchical clustering procedures typically produce
a list of the clusters merged at each stage of the clustering.
cluinf uses this list to construct arrays that explicitly show
which cluster a given data point belongs to, and which data points belong
to a given cluster.
Usage
cluinf(merge, nclust)
Arguments
merge
Matrix with 2 columns. The ith row contains
the labels of the clusters merged at the ith merge.
Can also be the object returned by a call to cluagg.
nclust
Number of clusters.
Value
Information about the clustering that has nclust clusters.
It is a list with the following elements:
assign
Vector giving the assignment of items to clusters.
list
List with nclust elements. Each element contains
the labels of the items in one cluster.
num
Vector of length nclust, containing the
number of items in each cluster.
Hosking, J. R. M., and Wallis, J. R. (1997).
Regional frequency analysis: an approach based on L-moments.
Cambridge University Press.
See Also
cluagg
Examples
## Clustering of gaging stations in Appalachia, as in Hosking
## and Wallis (1997, sec. 9.2.3)
data(Appalach)
# Form attributes for clustering (Hosking and Wallis's Table 9.4)
att <- cbind(a1 = log(Appalach$area),
a2 = sqrt(Appalach$elev),
a3 = Appalach$lat,
a4 = Appalach$long)
att <- apply(att, 2, function(x) x/sd(x))
att[,1] <- att[,1] * 3
# Clustering by Ward's method
(cl<-cluagg(att))
# Details of the clustering with 7 clusters
cluinf(cl, 7)