[R] deconvoluting hclust objects

[Karin Lagesen]

I have a hclust object that looks like this:

> test77

Call:
hclust(d = input)

Cluster method   : complete
Number of objects: 11

> test77$height
 [1] 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.9000000
 [8] 0.9473684 1.7894737 8.5771948
> test77$merge
      [,1] [,2]
 [1,]   -1   -2
 [2,]   -3    1
 [3,]   -7    2
 [4,]   -8    3
 [5,]   -4   -6
 [6,]   -5  -10
 [7,]   -9    5
 [8,]  -11    4
 [9,]    7    8
[10,]    6    9
>

I am specifically interested in what happens when you divide this
object into three clusters. When I look at the plot, the three
clusters form like this: (monospace font)

    ----------
    |        |
    |       ----
    |       |  |
    2       3  6

What I am wanting is to get distance information on the three groups,
and also the number of objects in each. The distances I need are in
height, but I don't know how to get at the sizes of the subtrees. 

I know I can use cutree to get at the cut, but I cannot see anything
systematic in which group becomes group no 1 and so forth.

The results I want would in this example be:

2    3    6     8.5771948   1.7894737

Any hints for me?

Thanks!

Karin
-- 
Karin Lagesen, PhD student
karin.lagesen at medisin.uio.no
http://folk.uio.no/karinlag