Agglomerative Hierarchical Algorithms（凝聚式层次聚类）

（1）Agglomerative Hierarchical Clustering：凝聚式层次聚类，自底向上

（2）Divisive Hierarchical Clustering：分裂式层次聚类，自顶向下

A hierarchical clustering algorithm is a clustering algorithm that divides a dataset into a sequence of nested partitions. Hierarchical clustering algorithms can be classified into two categories：agglomerative hierarchical algorithms and divisive hierarchical algorithms.