Hi ! I am trying to cluster data on R from a distance matrix. I tried hclust (and cuttree) or pam. The problem is, I don't know how many clusters to ask for. I know a lot of methods are found to determine the optimal number of clusters and clustering method (mclust, pvclust, fviz_nbclust, optCluster) but starting from a quantitative data. In my case I want to do the same but starting from a distance matrix. As these methods I cited go through a distance matrix it would sound weird to do a distance of a distance. Do you know other methods ?

Cheers !

Thank you, I think I agree. I only have a distance matrix because I am comparing images pairwise and the first step is to output a distance.