Computes an approximation for a specified quartile across all row values in a column or group. Input column can be of Integer or Decimal. |
pivot
transform, the function is computed for each instance of the value specified in the group
parameter. See Pivot Transform.The approximate percentile functions utilize a different algorithm for efficiently estimating quantiles for streaming and distributed processing, depending on the running environment where the function is computed.
Tip: Approximation functions are suitable for larger datasets. As the number of rows increases, accuracy and calculation performance improves for these functions. |
Quartiles are computed as follows:
Quartile | Description |
---|---|
0 | Minimum value |
1 | 25th percentile |
2 | Median value |
3 | 75th percentile and higher |
approximatequartile(myScores, 3) |
Output: Computes the approximate value that is at the 3rd quartile across all values in the myScores column.
approximatequartile(function_col_ref,num_quartile) [group:group_col_ref] [limit:limit_count] |
Argument | Required? | Data Type | Description |
---|---|---|---|
function_col_ref | Y | string | Name of column to which to apply the function |
num_quartile | Y | integer | Integer value (0-3) of the quartile to compute |
dec_error_bound | N | decimal | Error factor for computing approximations. Decimal value represents error factor as a percentage (0.4 is 0.4%). |
For more information on the group
and limit
parameters, see Pivot Transform.
Name of the column the values of which you want to calculate the quartile. Column must contain Integer or Decimal values.
Required? | Data Type | Example Value |
---|---|---|
Yes | String (column reference) | precipitationIn
|
Integer literal value indicating the quartile that you wish to compute. Input value must be between 0
and 3
, inclusive.
Required? | Data Type | Example Value |
---|---|---|
Yes | Integer | 3 |
As needed, you can insert an error boundary factor as a parameter into the computation of this approximate value.
0.5
(0.5%). Required? | Data Type | Example Value |
---|---|---|
No | Decimal (literal) | 0.01
|