R devel - Aug 2001 - cutree (PR#1067)

Full_Name: Anja von Heydebreck
Version: 1.3.0
OS: Alpha Unix
Submission from: (NULL) (141.14.19.61)


Hi,

I repeatedly obtained meaningless results from the function 'cutree' 
in the 'mva' package, when the argument 'h' was greater or equal
to
the maximum height occuring: 
> library('mva')
> y
     [,1] [,2] [,3] [,4]
[1,]    0    1   -1    1
[2,]    0   -1    1    0
[3,]    0   -1    1    1
[4,]   -1   -2    1    0
> d <- dist(y, method="manhattan")
> hc <- hclust(d, method = "complete")
> hc$height
[1] 1 3 7
> cluster <- cutree(hc, h=max(hc$height))
> cluster
[1] 1108612352          1 1074517880          1

Best regards,

Anja


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>>>>> "Anja" == Anja von Heydebreck
<heydebre@molgen.mpg.de> writes:
    Anja> Full_Name: Anja von Heydebreck Version: 1.3.0 OS: Alpha Unix
    Anja> Submission from: (NULL) (141.14.19.61)

Thank you

    Anja> I repeatedly obtained meaningless results from the function
    Anja> 'cutree' in the 'mva' package, when the argument
'h' was greater
    Anja> or equal to the maximum height occuring:

Here is an executable version of Anja's example:

 library('mva')
 y <-
 rbind(c( 0,  1, -1, 1),
       c( 0, -1,  1, 0),
       c( 0, -1,  1, 1),
       c(-1, -2,  1, 0))
 d <- dist(y, method="manhattan")
 hc <- hclust(d, method = "complete")
 hc$height
 ## [1] 1 3 7
 ( cluster <- cutree(hc, h=max(hc$height)))

  ## Anja got
  ## [1] 1108612352          1 1074517880          1

  ## Martin: I get
  ## [1] 0 0 0 0

even though I don't get random results, it's still wrong.
I'll look at a fix.

Martin Maechler <maechler@stat.math.ethz.ch>
http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum  LEO D10	Leonhardstr. 27
ETH (Federal Inst. Technology)	8092 Zurich	SWITZERLAND
phone: x-41-1-632-3408		fax: ...-1228			<><

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