Cluster analysis.

Cluster analysis is a means of examining and evaluating information focused on combining the information into groups based on how similar the individual facts are to one another. The groups, or clusters, of related items that are formed are helpful to the analyst in understanding the information. Cluster analysis can also be used to help summarize large amounts of information as part of another purpose, such as categorizing information to find the most relevant facts. This form of analysis has applications in biology, health sciences, psychology, sociology, anthropology and statistics. It also has applications in data mining and other forms of information retrieval and analysis, and pattern recognition. The result of a cluster analysis. By hellisp, Wgabrie, Public domain, via Wikimedia Commons Cluster analysis with EM on a density-based data set. By Chire, CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0), from Wikimedia Commons