From friedrich.leisch at stat.uni-muenchen.de  Wed Dec 16 15:55:30 2009
From: friedrich.leisch at stat.uni-muenchen.de (Friedrich Leisch)
Date: Wed, 16 Dec 2009 15:55:30 +0100
Subject: [Rd] Flexclust barchart issue when mcol=NULL
In-Reply-To: <20091216060511.A32D0282EFF6@mail.pubhealth.ku.dk>
References: <20091216060511.A32D0282EFF6@mail.pubhealth.ku.dk>
Message-ID: <19240.62690.283393.334035@ridcully.stat.uni-muenchen.de>

>>>>> On Wed, 16 Dec 2009 07:05:11 +0100 (CET),
>>>>> christopher a hane (cah) wrote:

  > Full_Name: Chris Hane
  > Version: 2.10.1
  > OS: Windows
  > Submission from: (NULL) (198.203.181.181)


  > When using barchart in the flexcust package, setting mcol=NULL to avoid the
  > lollipops causes an error.  Each panel shows the text message "Error using
  > packet n replacement has length zero." where n is the panel number.

  >> data(iris)
  >> cl <- cclust(iris[,-5], k=3)
  >> barplot(cl, mcol=NULL)  #works fine
  >> barchart(cl, mcol=NULL) # oops

Yes, that's a bug in flexclust. I'll fix it for the next release.

In the meantime you can use barchart(cl, mcol=NA) which has the same
effect for me. 
  

  > FWIW, as the data of the clusters is scaled showing the colMeans
  > for the centers is misleading.  The global mean of each column is
  > 0, not the colMean of the centers.

Hmm, I am not sure I understand this paragraph. I agree that showing
the global mean makes no sense for centered data, but the iris data
are not centered. I don't think that barcharts like the above make
sense in all possible situations. I mainly use them for binary data
where I want to see which variables have a high/low percentage of ones
in which cluster (=bars), and what the difference to the global mean
is.

Best,
Fritz



[Rd] Flexclust barchart issue when mcol=NULL
Friedrich Leisch