STDEV_q

Updated 2023-10-24 20:12:20.750000

Syntax

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

Description

Use STDEV_q to return the estimated standard deviation based on a sample. The standard deviation is a measure of how widely values are dispersed from the mean. The equation for STDEV_q is:

 \sqrt{\frac{1}{N-1}\sum_{j=0}^{N-1}(x_j-\bar{x})^2

Arguments

@Values_RangeQuery

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

Return Type

float

Remarks

If you want measure the standard deviation for an entire population, then use the STDEVP_q function.

For simpler queries or for queries on de-normalized data, use the STDEV function.

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.STDEV_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":"11.0303511188038"}]}