Similarity measure
REAL-VALUED FUNCTION THAT QUANTIFIES THE SIMILARITY BETWEEN TWO OBJECTS
Similarity matrix; Similarity function; Measure of similarity; Similarity metric
In statistics and related fields, a similarity measure or similarity function or similarity metric is a real-valued function that quantifies the similarity between two objects. Although no single definition of a similarity exists, usually such measures are in some sense the inverse of distance metrics: they take on large values for similar objects and either zero or a negative value for very dissimilar objects.