Relational Data - Aggregate Functions - Reference - Rank Corr

Computes a rank correlation coefficient.

Syntax

rankCorr(x, y)

Arguments

• x — Arbitrary value. Float32 or Float64.
• y — Arbitrary value. Float32 or Float64.

Returned value(s)

• Returns a rank correlation coefficient of the ranks of x and y. The value of the correlation coefficient ranges from -1 to +1. If less than two arguments are passed, the function will return an exception. The value close to +1 denotes a high linear relationship, and with an increase of one random variable, the second random variable also increases. The value close to -1 denotes a high linear relationship, and with an increase of one random variable, the second random variable decreases. The value close or equal to 0 denotes no relationship between the two random variables.

Type: Float64.

Example

Query:

SELECT rankCorr(number, number) FROM numbers(100);

Result:

┌─rankCorr(number, number)─┐
│                        1 │
└──────────────────────────┘

Query:

SELECT roundBankers(rankCorr(exp(number), sin(number)), 3) FROM numbers(100);

Result:

┌─roundBankers(rankCorr(exp(number), sin(number)), 3)─┐
│                                              -0.037 │
└─────────────────────────────────────────────────────┘

See Also

• Spearman’s rank correlation coefficient