tree_prune {PPCI}

Prune a Hierarchical Clustering Model

Description

Removes the subtree rooted at the specified node from a hierarchical clustering model generated by one of mcdc, mddc and ncutdc.

Usage

tree_prune(sol, node)

Arguments

sol

a clustering solution arising from one of the functions mcdc, mddc and ncutdc.

node

the node at which to prune the hierarchy. can be either an integer specifying the node number in sol$nodes or a vector of length two specifying c(depth, position at depth) of the node.

Value

a list with the same components as sol.

Examples

## load the optidigits dataset
data(optidigits)

## cluster using minimum normalised cut hyperplanes,
## assuming no domain knowledge begin with 12 clusters
sol <- ncutdc(optidigits$x, 12)

## the node numbered 11 has been split,
## yet it appears there may not be multiple clusters present.
## inspect this node more closely
plot(sol, node = 11)

## remove this node from the model
sol_new <- tree_prune(sol, 11)

## compare the solutions using external cluster validity metrics

cluster_performance(sol$cluster, optidigits$c)

cluster_performance(sol_new$cluster, optidigits$c)