Computes the rolling unique kth largest value forward or backward of the current row.

For purposes of this calculation, two instances of the same value are treated at one value for k. So, if your dataset contains four rows with column values 1099, and 8, then KTHLARGESTUNIQUE returns 9 for k=2 and 8 for k=3.

ROLLINGKTHLARGESTUNIQUE computes the KTHLARGESTUNIQUE value across a defined window of values within a column.

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

Column example:

rollingkthlargestunique(myCol, 2)

Output: Returns the rolling second largest unique value in the myCol column from the first row of the dataset to the current one.

Rows before example:

rollingkthlargestunique(myNumber, 2, 3)

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

Rows before and after example:

rollingkthlargestunique(myNumber, 4, 3, 2)

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

rollingkthlargestunique(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 unique 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. 

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 a single value 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