 Computes the rolling standard deviation of values forward or backward of the current row within the specified column using the sample statistical method.
• If an input value is missing or null, it is not factored in the computation. For example, for the first row in the dataset, the rolling standard deviation of previous values is undefined.
• The row from which to extract a value is determined by the order in which the rows are organized based on the `order` parameter.

• If you are working on a randomly generated sample of your dataset, the values that you see for this function might not correspond to the values that are generated on the full dataset during job execution.

• The function takes a column name and two optional integer parameters that determine the window backward and forward of the current row.
• The default integer parameter values are `-1` and `0`, which computes the rolling function from the current row back to the first row of the dataset.
• This function works with the following transforms:
 NOTE: This function applies to a sample of the entire population. More information is below. For more information on a non-rolling version of this function, see STDEV Function.  Column example:

 rollingstdevsamp(myCol)

Output: Returns the rolling standard deviation of all values in the `myCol` column using the sample method of calculation.

Rows before example:

 rollingstdevsamp(myNumber, 100)

Output: Returns the rolling standard deviation of the current row and the 100 previous row values in the `myNumber` column using the sample method of calculation.

Rows before and after example:

 rollingstdevsamp(myNumber, 3, 2)

Output: Returns the rolling standard deviation of the three previous row values, the current row value, and the two rows after the current one in the `myNumber` column. rollingstdevsamp(col_ref, rowsBefore_integer, rowsAfter_integer) order: order_col [group: group_col]

ArgumentRequired?Data TypeDescription
col_refYstringName of column whose values are applied to the function
rowsBefore_integerNintegerNumber of rows before the current one to include in the computation
rowsAfter_integerNintegerNumber of rows after the current one to include in the computation

For more information on the `order` and `group` parameters, see Window Transform. ### col_ref

Name of the column whose values you wish to use in the calculation. Column must be a numeric (Integer or Decimal) type.

• Multiple columns and wildcards are not supported. Required?Data TypeExample Value
YesString (column reference to Integer or Decimal values)`myColumn`

### rowsBefore_integer, rowsAfter_integer

Integers representing the number of rows before or after the current one from which to compute the rolling function, including the current row. For example, if the first value is `5`, the current row and the five before after it are used in the computation. Negative values for `k` compute the rolling average from rows preceding the current one.

• `rowBefore=0` generates the current row value only.
• `rowBefore=-1`  uses all rows preceding the current one.
• If `rowsAfter` is not specified, then the value `0` is applied.
• If a `group` parameter is applied, then these parameter values should be no more than the maximum number of rows in the groups. Required?Data TypeExample Value
NoInteger`4` ### Example - Rolling computations for racing splits  