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slug | sidebar_position |
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/en/sql-reference/aggregate-functions/reference/cramersvbiascorrected | 128 |
cramersVBiasCorrected
Cramer's V is a measure of association between two columns in a table. The result of the cramersV
function ranges from 0 (corresponding to no association between the variables) to 1 and can reach 1 only when each value is completely determined by the other. The function can be heavily biased, so this version of Cramer's V uses the bias correction.
Syntax
cramersVBiasCorrected(column1, column2)
Parameters
column1
: first column to be compared.column2
: second column to be compared.
Returned value
- a value between 0 (corresponding to no association between the columns' values) to 1 (complete association).
Type: always Float64.
Example
The following two columns being compared below have a small association with each other. Notice the result of cramersVBiasCorrected
is smaller than the result of cramersV
:
Query:
SELECT
cramersV(a, b),
cramersVBiasCorrected(a ,b)
FROM
(
SELECT
number % 10 AS a,
number % 4 AS b
FROM
numbers(150)
);
Result:
┌──────cramersV(a, b)─┬─cramersVBiasCorrected(a, b)─┐
│ 0.41171788506213564 │ 0.33369281784141364 │
└─────────────────────┴─────────────────────────────┘