[R] 2D fellows

Winfried Theis
Tue, 16 May 2000 09:14:27 -0000

Dear Liem!
On 15-May-00 TRAN Liem FTM/Men wrote:
> Hello everybody,
>
>
> I would like to perform some treatments on a group. Each element of my
> group is a 2D array. They all have the same dimensions.
I don''t know what you mean exactly by a "2D-array", I would
think first of
something you could easily convert to a matrix, or a data frame! (I just had a
look on "Notes on R" and the description of arrays there confirms my
belief
about the convertion.)
>
> I would like to know if I can find in R some functions like
"dist" (base
> package), "hclust" and "kmeans" (mva package) but in
order to use 2D
> arrays more than vectors.
Well, if you could convert your arrays into vectors (via matrix or data frame
 if you want to) and collect them in a data frame you could use these functions.
If you need a special distance you could program a function in which you compute
the pairwise distances and write them to a dissimilarity matrix as in the
package cluster. For a description see the documentation there (or just type
daisy after loading the package cluster). With this you could use the functions
diana for divisive hierarchical
clustering, agnes for agglomerative nesting or for k-means pam.

I hope this helps,

yours Winfried Theis
----------------------------------
E-Mail: Winfried Theis <theis at statistik.uni-dortmund.de>
Date: 16-May-00
Tel.: +49-231-755-5903                  Room: Mathematikgebäude, M832
Dipl.-Math. Winfried Theis, Graduiertenkolleg "Angewandte Statistik",
Universität Dortmund, 44221 Dortmund
----------------------------------