entropy
Calculates the [Shannon entropy](https://en.
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
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┌─entropy(vals)─┬─entropy(strings)─┐
│ 1 │ 1.75 │
└───────────────┴──────────────────┘Introduced in version 20.1.