From friedrich.leisch at stat.uni-muenchen.de  Mon Apr 23 10:29:09 2007
From: friedrich.leisch at stat.uni-muenchen.de (Friedrich Leisch)
Date: Mon, 23 Apr 2007 10:29:09 +0200
Subject: [Rd] dendrogram definition
In-Reply-To: <eb555e660704201446j58dd4cb2p6efb5d389c0a010f@mail.gmail.com>
References: <eb555e660704201446j58dd4cb2p6efb5d389c0a010f@mail.gmail.com>
Message-ID: <17964.28245.673639.140342@lxh5.stat.uni-muenchen.de>

>>>>> On Fri, 20 Apr 2007 14:46:33 -0700,
>>>>> Deepayan Sarkar (DS) wrote:

  > Hi,
  > I'm trying to create a "grob" representing a dendrogram object (for
  > use as a legend with lattice), and I have a question regarding how a
  > "dendrogram" should be interpreted. Are they by definition binary
  > trees or can they in principle have more than two children?

They can have more than 2 children, and class "dendrogram" supports
this. However, as most trees are currently created using hclust, all
examples have binary trees.

E.g.,

example(dendrogram)
d3e[[3]]=d3e
attr(d3e,"members")=14
str(d3e)

creates a tree with three branches in the root node (not all
attributes are correct after that brute force operation, so plots will
not look as nice as possible).

Best,
Fritz



[Rd] dendrogram definition
Friedrich Leisch