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SKEW_q

Updated 2023-10-24 13:59:07.690000

Syntax

SELECT [westclintech].[wct].[SKEW_q] (
   <@Values_RangeQuery, nvarchar(4000),>)

Description

Use SKEW_q to return the degree of asymmetry of a distribution. If the distribution has a longer tail less than the maximum, the function has negative skewness. Otherwise it has positive skewness. The equation for skewness is:

 \frac{n}{(n-1)(n-2)}\sum_{j=1}^n[\frac{x_j-\bar{x}}{\sigma}]^3

Arguments

@Values_RangeQuery

the select statement, as text, used to determine the values to be used in the SKEW_q calculation.

Return Type

float

Remarks

If there are fewer than three rows in the dataset, then SKEW_q returns an error.

If the sample standard deviation is zero, then SKEW_q returns an error.

For simpler queries use SKEW.

No GROUP BY is required for this function even though it produces aggregated results.

Examples

CREATE TABLE #k1

(

    [num] [float] NOT NULL

);

INSERT INTO #k1

VALUES

(91.3698);

INSERT INTO #k1

VALUES

(76.3382);

INSERT INTO #k1

VALUES

(74.5692);

INSERT INTO #k1

VALUES

(85.2957);

INSERT INTO #k1

VALUES

(99.0112);

INSERT INTO #k1

VALUES

(86.99);

INSERT INTO #k1

VALUES

(70.7837);

INSERT INTO #k1

VALUES

(72.834);

INSERT INTO #k1

VALUES

(78.1644);

INSERT INTO #k1

VALUES

(77.7472);

INSERT INTO #k1

VALUES

(66.0627);

INSERT INTO #k1

VALUES

(59.781);

INSERT INTO #k1

VALUES

(68.4793);

INSERT INTO #k1

VALUES

(78.6103);

INSERT INTO #k1

VALUES

(59.8621);

select wct.SKEW_q('Select num from #k1');

This produces the following result

{"columns":[{"field":"column 1","headerClass":"ag-right-aligned-header","cellClass":"ag-right-aligned-cell"}],"rows":[{"column 1":"0.363338937261944"}]}