Create Groups from Hierarchical Clustering
DESCRIPTION:
Returns a vector of group numbers for the observations that were clustered. Either the number of groups desired, or a clustering height are to be specified.
USAGE: 
cutree(tree, k = 0, h = 0)
REQUIRED ARGUMENTS:
tree:
hierarchical clustering tree structure, typically the output of hclust.

Exactly one of k or h must be supplied.

OPTIONAL ARGUMENTS:
k:
the desired number of groups. Default is 0.
h:
the height at which to cut tree in order to produce the groups. Groups will be defined by the structure of the tree above the cut. Default is 0.
VALUE:
vector with as many elements as there are leaves in the tree. The ith element of the vector gives the group number to which individual i is assigned. Individuals not in the current tree (if tree was a subtree from a larger original problem) are assigned group 0. Attribute height is a vector with as many values as there are resulting groups, the ith value gives the height of the last merge making up the group. Singleton clusters are given height 0.
SEE ALSO:
category , dist , hclust , subtree .
EXAMPLES: 
vote.cl <- hclust(dist(votes.repub))
group <- cutree(vote.cl, k=5)  # produce 5 groups
state.name[group==1]