R help - Mar 2005 - plot(bclust) what is the 2nd plot?

Hi everyone,
 
Currently i'm trying to understand the bagged clustering algorithm, bclust
{e1071}. 
 
When I run the given example in the help file (as below)
  data(iris)
     bc1 <- bclust(iris[,1:4], 3, base.centers=5)
     plot(bc1)

and plot the bclust object, 2 graphs are produced. 
The first is a dendrogram, but what is the second plot? The axes are not
labelled and what do the two lines represent? I tried looking in the URL
given in the references but that didn't help.
 
Thanks for your help!
 
Jacqui Hall
 
 



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>>>>> On Wed, 9 Mar 2005 10:36:49 -0000,
>>>>> Jacqueline Hall (JH) wrote:
  > Hi everyone,
  > Currently i'm trying to understand the bagged clustering algorithm,
bclust
  > {e1071}. 
 
  > When I run the given example in the help file (as below)
  >   data(iris)
  >      bc1 <- bclust(iris[,1:4], 3, base.centers=5)
  >      plot(bc1)

  > and plot the bclust object, 2 graphs are produced. 
  > The first is a dendrogram, but what is the second plot? The axes are not
  > labelled and what do the two lines represent?

 
The monotonic decreasing line gives the relative height of the split
of tyhe tree into 2, 3, etc. branches, the second line is the first
differences of the first. A peak in the differencescan be used as a
crude estimation for the number of clusters.

  > I tried looking in the URL
  > given in the references but that didn't help.

Look at Section IV.A of the working paper.

HTH,

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