Re: [R] hclust with method = “ward”

Apparently, the same issue exists in SAS, where there is an option to run the Ward algorithm based only on the distance matrix. Perhaps, a SAS user could confirm that or even check with SAS. Peter -- View this message in context:

Re: [R] hclust with method = “ward”

whether it really is what hclust does, because I didn't check the underlying Fortran code. Note that I may have missed postings in this thread, so sorry if this doesn't add to what you already have worked out. Christian On Wed, 6 Oct 2010, PeterB wrote: Apparently, the same issue

[R] hclust with method = “ward”

The clustering function hclust has a method = ward”, and apparently many people use that option. However, the Ward method seems to minimize an increase in the error sums of squares, which are calculated with respect to the cluster mean. However, hclust has only a dissimilarity matrix as an input.