[R-sig-Geo] complete linkage Agglomerative hierarchical clustering, nnclust, spatclus or something else?

[Roger Bivand]

On Wed, 21 Apr 2010, Hans Ekbrand wrote:

> On Wed, Apr 21, 2010 at 01:42:05PM +0200, Roger Bivand wrote:
>> So you do not want hclust at all, really. Look at dnearneigh() in spdep,
>> setting a 100m bound. Then use n.comp.nb() to see which points belong to
>> which graph component, using perhaps plot.nb with colours to distinguish
>> the subgraphs.
>
> Well, hclust was useful, once I understood how cutree works. What
> would be the benefit of dnearneigh(), is it faster?
>

For larger data sets, hclust needs a triangular distance matrix, 
dnearneigh does not. Finding graph components in the output "nb" object 
also seems conceptually more direct. But if your solution works for you, 
that is fine.

Roger

-- 
Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no