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Excerpt

Computes the standard deviation across all column values of Integer or Decimal type.

The standard deviation of a set of values attempts to measure the spread in values around the mean and is used to measure confidence in statistical results. A standard deviation of zero means that all values are the same, and a small standard deviation means that the values are closely bunched together. A high value for standard deviation indicates that the numbers are spread out widely. Standard deviation is always a positive value.

Standard deviation comes in two flavors:

• Population standard deviation computes the variance from all possible values.
• Sample standard deviation computes from a subset or sample of all values.
• Since
D s product
r true
has access to all available values, the computation for population standard deviation is used across the entire dataset.

If a row contains a missing or null value, it is not factored into the calculation. If no numeric values are detected in the input column, the function returns `0`.

The square of standard deviation is variance. See VAR Function.

For a version of this function computed over a rolling window of rows, see ROLLINGSTDEV Function.

D s
snippet Basic

D code

pivot value:STDEV(myRating) group: postal_code limit:1

Output: Generates a two-column table containing the unique values from the `postal_code` column and the standard deviation of the group of values from the `myRating` column for the `postal_code` value. The `limit` parameter defines the maximum number of output columns.

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snippet Syntax

D code

pivot value:STDEV(function_col_ref) [group:group_col_ref] [limit:limit_count]

ArgumentRequired?Data TypeDescription
function_col_refYstringName of column to which to apply the function

For more information on the `group` and `limit` parameters, see Pivot Transform.

D s lang notes

### function_col_ref

Name of the column the values of which you want to calculate the variance. Column must contain Integer or Decimal values.

• Literal values are not supported as inputs.
• Multiple columns and wildcards are not supported.

D s
snippet usage

Required?Data TypeExample Value
YesString (column reference)`myValues`

D s
snippet Examples

Include Page
 EXAMPLE - Statistical Functions EXAMPLE - Statistical Functions

D s also
label aggregate