Re-Order Leaves of a Cluster Tree

DESCRIPTION:

Returns a cluster tree that is re-ordered by the average value of x at each merge.

USAGE:

clorder(tree, x) 

REQUIRED ARGUMENTS:

tree
list with components named merge, height, and order, typically a hierarchical clustering tree produced by function hclust.
x
numeric vector with one value for each individual involved in the cluster tree. Missing values ( NAs) are not allowed.

VALUE:

cluster tree structure with the merge and order components permuted so that at any merge, the cluster with the smaller average x value is on the left. This re-orders tree so that the leaves are approximately in order by the associated x values.

SEE ALSO:

for the basic definition of the clustering method and structure.

EXAMPLES:

h <- hclust(dist(votes.repub)) 
ave.repub <- apply(votes.repub, 1, mean, na.rm=T) 
# leaves ordered by average republican vote 
h2 <- clorder(h, ave.repub) 
plclust(h2, lab=state.abb)  #cluster plot