entropy

Introduced in: v20.1.0 Calculates the Shannon entropy for a column of values. Syntax

entropy(val)

Arguments

val — Column of values of any type. Any

Returned value Returns Shannon entropy. Float64 Examples Basic entropy calculation

Query

CREATE TABLE entropy (`vals` UInt32,`strings` String)
ENGINE = Memory;

INSERT INTO entropy VALUES (1, 'A'), (1, 'A'), (1,'A'), (1,'A'), (2,'B'), (2,'B'), (2,'C'), (2,'D');

SELECT entropy(vals), entropy(strings) FROM entropy

Response

┌─entropy(vals)─┬─entropy(strings)─┐
│             1 │             1.75 │
└───────────────┴──────────────────┘

​entropy

entropy