## characteristic-function

Noun

(*plural* characteristic functions)

- (analysis) A function which is equal to 1 for all points in its domain which belong to a given set, and is equal to 0 for all points in the domain which do not belong to that given set.
- (mathematics, probability theory) A complex function completely defining the probability distribution of a real-valued random variable

Usage notes

- The characteristic function of a set
*A*is often represented as χ_{A}.