Cluster analysis is the process of grouping objects together in a way that objects in one group are more similar than objects in other groups.
An example would be identifying and grouping clients with similar booking activities on a travel portal, as shown in the following figure.
In the preceding example, each group is called a cluster, and each member (data point) of the cluster behaves in a manner similar to its group members.
Cluster analysis
Cluster analysis is an unsupervised learning method. In supervised methods, such as regression analysis, we have input variables and response variables. We fit a statistical model to the input variables to predict the response variable. Whereas in unsupervised learning methods, however, we do not have any response variable to predict; we only have input variables. Instead of fitting a model to the input variables to predict the response variable, we just try to find patterns within the dataset. There are three popular clustering algorithms...
