entropy
Calculates Shannon entropy of a column of values.
Syntax
entropy(val)
Arguments
val
β Column of values of any type.
Returned value
- Shannon entropy.
Type: Float64.
Example
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;
Result:
ββentropy(vals)ββ¬βentropy(strings)ββ
β 1 β 1.75 β
βββββββββββββββββ΄βββββββββββββββββββ