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 10
, 9
, 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.
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.
-1
and 0
, which computes the rolling function from the current row back to the first row of the dataset.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] |
Argument | Required? | Data Type | Description |
---|---|---|---|
col_ref | Y | string | Name of column whose values are applied to the function |
k_integer | Y | integer (positive) | The ranking of the value to extract from the source column |
rowsBefore_integer | N | integer | Number of rows before the current one to include in the computation |
rowsAfter_integer | N | integer | Number of rows after the current one to include in the computation |
For more information on the order
and group
parameters, see Window Transform.
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 Type | Example Value |
---|---|---|
Yes | String (column reference to Integer or Decimal values) | myColumn |
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=1
represents the maximum value in the column. k
.
Required? | Data Type | Example Value |
---|---|---|
Yes | Integer (positive) | 4
|
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 rowsAfter_integer
compute the rolling function from rows preceding the current one.
rowBefore=1
generates the current row value only.rowBefore=-1
uses all rows preceding the current one.rowsAfter
is not specified, then the value 0
is applied.group
parameter is applied, then these parameter values should be no more than the maximum number of rows in the groups.Required? | Data Type | Example Value |
---|---|---|
No | Integer | 4 |