reorder.dendrogram {stats}

R Documentation

Reorder a Dendrogram

Description

A method for the generic function reorder.

There are many different orderings of a dendrogram that are consistent with the structure imposed. This function takes a dendrogram and a vector of values and reorders the dendrogram in the order of the supplied vector, maintaining the constraints on the dendrogram.

Usage

## S3 method for class 'dendrogram'
reorder(x, wts, agglo.FUN = sum, ...)

Arguments

x	the (dendrogram) object to be reordered
wts	numeric weights (arbitrary values) for reordering.
agglo.FUN	a function for weights agglomeration, see below.
...	additional arguments

Details

Using the weights wts, the leaves of the dendrogram are reordered so as to be in an order as consistent as possible with the weights. At each node, the branches are ordered in increasing weights where the weight of a branch is defined as f(w_j) where f is agglo.FUN and w_j is the weight of the j-th sub branch.

Value

A dendrogram where each node has a further attribute value with its corresponding weight.

Author(s)

R. Gentleman and M. Maechler

See Also

reorder.

rev.dendrogram which simply reverses the nodes' order; heatmap, cophenetic.

Examples

require(graphics)

set.seed(123)
x <- rnorm(10)
hc <- hclust(dist(x))
dd <- as.dendrogram(hc)
dd.reorder <- reorder(dd, 10:1)
plot(dd, main = "random dendrogram 'dd'")

op <- par(mfcol = 1:2)
plot(dd.reorder, main = "reorder(dd, 10:1)")
plot(reorder(dd, 10:1, agglo.FUN = mean), main = "reorder(dd, 10:1, mean)")
par(op)

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