Mastering Machine Learning with R - Second Edition

Hierarchical clustering

To build a hierarchical cluster model in R, you can utilize the hclust() function in the base stats package. The two primary inputs needed for the function are a distance matrix and the clustering method. The distance matrix is easily done with the dist() function. For the distance, we will use Euclidean distance. A number of clustering methods are available, and the default for hclust() is the complete linkage. We will try this, but I also recommend Ward's linkage method. Ward's method tends to produce clusters with a similar number of observations.

The complete linkage method results in the distance between any two clusters that is the maximum distance between any one observation in a cluster and any one observation ...