Computes the rolling kth largest value forward or backward of the current row. Inputs can be Integer, Decimal, or Datetime.

KTHLARGEST extracts the ranked value from the values in a column, where k=1 returns the maximum value. The value for k must be between 1 and 1000, inclusive. For purposes of this calculation, two instances of the same value are treated as separate values. So, if your dataset contains three rows with column values 109, and 9, then KTHLARGEST returns 9 for k=2 and k=3.

ROLLINGKTHLARGEST computes the KTHLARGEST value across a defined window of values within a column.

For more information on a non-rolling version of this function, see KTHLARGEST Function.

Column example:

rollingkthlargest(myCol, 2)

Output: Returns the rolling second largest of all values in the myCol column.

Rows before example:

rollingkthlargest(myNumber, 2, 3)

Output: Returns the rolling second largest value of the current row and the two previous row values in the myNumber column.

Rows before and after example:

rollingkthlargest(myNumber, 4, 3, 2)

Output: Returns the rolling fourth largest value of the two previous row values, the current row value, and the two rows after the current one in the myNumber column.     

rollingkthlargest(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
k_integerYinteger (positive)The ranking of the value to extract from the source column
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 are used to compute the function. Inputs must be Integer, Decimal, or Datetime values.

NOTE: If the input is in Datetime type, the output is in unixtime format. You can wrap these outputs in the DATEFORMAT function to output the results in the appropriate Datetime format. See DATEFORMAT Function.

Required?Data TypeExample Value
YesString (column reference to Integer or Decimal values)myColumn

k_integer

Integer representing the ranking of the unique value to extract from the source column. Duplicate values are treated as separate values for purposes of this function's calculation.

NOTE: The value for k must be an integer between 1 and 1,000 inclusive.

 

Required?
Data Type
Example Value
YesInteger (positive)4

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 four rows after it are used in the computation. Negative values for k compute the rolling average from rows preceding the current one.

Required?Data TypeExample Value
NoInteger4

Example - ROLLINGKTHLARGEST functions