entropy

引入版本：v20.1.0 计算某一列值的香农熵。语法

entropy(val)

参数

val — 任意类型的值列。Any

返回值 返回香农熵。Float64 示例 基础熵计算

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