Cluster analysis , or clustering , is a data analysis technique aimed
at partitioning a set of objects into groups such that objects within the same
group (called a cluster) exhibit greater similarity to one another (in
some specific sense defined by the analyst) than to those in other groups
(clusters). It is a main task of exploratory data analysis, and a common
technique for statistical data analysis, used in many fields, including
pattern recognition, image analysis, information retrieval, bioinformatics,
data compression, computer graphics and machine learning.
Cluster analysis refers to a family of algorithms and tasks rather than one
specific algorithm.