STDEVX.S Function (DAX)

  • Article

Returns the standard deviation of a sample population.

Syntax

STDEVX.S(<table>, <expression>)

Parameters

  • table
    Any DAX expression that returns a single scalar value, where the expression is to be evaluated multiple times (for each row/context).

  • expression
    Any DAX expression that returns a single scalar value, where the expression is to be evaluated multiple times (for each row/context).

Return Value

A number with the standard deviation of a sample population.

Remarks

  1. STDEVX.S evaluates expression for each row of table and returns the standard deviation of expression assuming that table refers to a sample of the population. If table represents the entire population, then compute the standard deviation by using STDEVX.P.

  2. STDEVX.S uses the following formula:

    √[∑(x - x̃)²/(n-1)]

    where x̃ is the average value of x for the entire population

    and n is the population size

  3. Blank rows are filtered out from columnName and not considered in the calculations.

  4. An error is returned if columnName contains less than 2 non-blank rows.

This DAX function may return different results when used in a model that is deployed and then queried in DirectQuery mode. For more information about semantic differences in DirectQuery mode, see  https://go.microsoft.com/fwlink/?LinkId=219171.

Example

The following example shows the formula for a calculated column that estimates the standard deviation of the unit price per product for a sample population, when the formula is used in the Product table.

=STDEVX.S(RELATEDTABLE(InternetSales_USD), InternetSales_USD[UnitPrice_USD] – (InternetSales_USD[DiscountAmount_USD]/InternetSales_USD[OrderQuantity]))