trimZ.m

trims the SAHN tree, Z, generated by the function, linkage to correspond to cluster(Z,'maxclust',m)

The statistics toolbox contains routines for hierarchical clustering, including the cluster routine uses the SAHN tree to group data into clusters. However, the toolbox seems to lack a routine that uses the SAHN tree to describe the hierarchical relationship between those clusters. This routine trims the SAHN tree produced by linkage in order to produce a new "tree" (that can be displayed using, e.g., dendrogram) whose leaf nodes have numbers corresponding to the cluster IDs produced using cluster and whose internal topology matches the topology of the top num_clusters nodes in the original SAHN tree and thus represents the clustering (i.e. in the SAHN tree) of the clusters extracted using clusters