[x] AGNES (AGglomerative NESting): Continuously merge nodes that have the least dissimilarity.
[ ] DIANA (Divisive ANAlysis): The process starts at the root with all the points as one cluster and recursively splits the higher level clusters to build the dendrogram.
[ ] BIRCH (Balanced Iterative Reducing and Clustering using Hierarchies): Incrementally construct a CF (Clustering Feature) tree, a hierarchical data structure for multiphase clustering