D toc

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.

D s
snippet Syntax

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

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

D s
snippet Examples

Include Page
EXAMPLE - Statistical Functions EXAMPLE - Statistical Functions

D s also
label aggregate