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Computes an approximation for a specified quartile across all row values in a column or group. Input column can be of Integer or Decimal.

If a row contains a missing or null value, it is not factored into the calculation. If the entire column contains no values, the function returns a null value.
When used in a 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.
- For an exact calculation of this function, see QUARTILE Function.

Quartiles are computed as follows:

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.

This value must be a Decimal literal value.
This decimal value represents the percentage error factor. By default, this value is 0.5 (0.5%).

Required?	Data Type	Example Value
No	Decimal (literal)	`0.01`