Clustering is the process of trying to make groups of objects that are more similar to each other than objects in other groups. Clustering is also called cluster analysis.
R has several tools to cluster your data (which we will investigate in this chapter):
K-means, including optimal number of clusters
Partitioning Around Medoids (PAM)
Bayesian hierarchical clustering
Affinity propagation clustering
Computing a gap statistic to estimate the number of clusters
Hierarchical clustering