Relational Data - Aggregate Functions - Reference - Contingency

The contingency function calculates the contingency coefficient, a value that measures the association between two columns in a table. The computation is similar to the cramersV function but with a different denominator in the square root.

Syntax

contingency(column1, column2)

Arguments

• column1 and column2 are the columns to be compared

Returned value

• a value between 0 and 1. The larger the result, the closer the association of the two columns.

Return type is always Float64.

Example

The two columns being compared below have a small association with each other. We have included the result of cramersV also (as a comparison):

SELECT
    cramersV(a, b),
    contingency(a ,b)
FROM
    (
        SELECT
            number % 10 AS a,
            number % 4 AS b
        FROM
            numbers(150)
    );

Result:

┌──────cramersV(a, b)─┬───contingency(a, b)─┐
│ 0.41171788506213564 │ 0.05812725261759165 │
└─────────────────────┴─────────────────────┘