[R] Enquiry about Hierarchical Clustering
Martin Maechler
maechler at stat.math.ethz.ch
Sat Sep 27 19:11:14 CEST 2003
>>>>> "Adaikalavan" == Adaikalavan RAMASAMY <ramasamya at gis.a-star.edu.sg>
>>>>> on Sat, 27 Sep 2003 17:05:43 +0800 writes:
Adaikalavan> Hclust is unable to handle missing values in
Adaikalavan> dist(). There will be missing values in dist()
Adaikalavan> function if 1. all elements in a row are
Adaikalavan> missing 2. all pairs between any two rows have
Adaikalavan> at least one missing values.
As Kjetial Halvorsen said, use daisy() from the cluster
package instead of dist().
The daisy() function has two advantages over dist():
1. Handling of missing values
2. Handling of data with continuous *and* categorical variables.
[Btw, this has not really anything to do with the clustering
method used *after* the distance has been computed.
You can use hclust() on a daisy result if you want]
Regards,
Martin Maechler <maechler at stat.math.ethz.ch> http://stat.ethz.ch/~maechler/
Seminar fuer Statistik, ETH-Zentrum LEO C16 Leonhardstr. 27
ETH (Federal Inst. Technology) 8092 Zurich SWITZERLAND
phone: x-41-1-632-3408 fax: ...-1228 <><
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