Re: Cluster Analysis - Seeds needed for K-Means

[Peterson, Leif E]

Title: RE: Cluster Analysis - Seeds needed for K-Means

Aaron,

SPSS is very limited in its output -- especially for hierarchical cluster analysis -- so I understand what you have been going through.  Try the Weka or BioMedStat program [which we developed for hierarchical, c-means (k-means), and fuzzy c-means].   

There are methods for finding the optimal number of clusters during K-means analysis (e.g., specify k=0 in BioMedStat) so you don't always have to seed k-means with the number of clusters obtained from hierarchical. 

Overall, Weka is a very good point and click program powered by Java.  BioMedStat is also run solely through Win XP, which is point and click.

With best regards

LP

-----Original Message-----
From: Classification, clustering, and phylogeny estimation on behalf of Aaron Eakman
Sent: Mon 8/7/2006 7:43 PM
To: CLASS-L@lists.sunysb.edu
Subject: Cluster Analysis - Seeds needed for K-Means

I am using SPSS 12 for my clustering procedures.  I started with
heirarchical clustering using Wards method with squared euclidean
distance.  I have identified a three cluster solution as the best option
from a possible range of 2-4 that I established a priori.

Here is my problem, I want to next run a K-means clustering procedure.
More specifically, I want to use the centroids of the three clusters from
my heirarchical procedure as "seed" or starting values for the K-means
clustering procedure.  Unfortunately, SPSS does not generate this output
from the heirarchical procedure.  And I do not know 1) how to generate
cluster centroids from the cluster assignment information provided by SPSS
heirarchical procedure, and 2) even if I did, I do not know how
to generate an SPSS.sav file with that information for use by the K-means
approach.  A further problem, I am a point and clicker and not savvy with
command syntax; I AM WILLING TO LEARN IF IT CAN GET ME OUT OF MY MESS!!

Any persons that are SPSS  - Cluster Analysis savvy, or know others that
might lend a hand would be met with gratitude for any assistance.

Take care,

Aaron Eakman

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