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d-excerpt

Computes the approximate median from 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

    Tip: Approximation functions are suitable for larger datasets. As the number of rows increases, accuracy and calculation performance improves for these functions. 



D s lang vs sql

D s
snippetBasic

D lang syntax
RawWrangletrue
Typeref
showNotetrue
WrangleTextpivot value:approximatemedian(myRating) group:postal_code limit:1

approximatemedian(myRating)

Output: Returns the approximate median of the values in the myRating column.

D s
snippetSyntax

D lang syntax
RawWrangletrue
Typesyntax
showNotetrue
WrangleTextpivot value:approximatemedian(function_col_ref) [group:group_col_ref] [limit:limit_count]

approximatemedian(function_col_ref) [group:group_col_ref] [limit:limit_count]


ArgumentRequired?Data TypeDescription
function_col_refYstringName of column to which to apply the function
dec_error_boundNdecimalError 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.

D s lang notes

function_col_ref

Name of the column the values of which you want to calculate the median. Column must contain Integer or Decimal values.

  • Literal values are not supported as inputs.
  • Multiple columns and wildcards are not supported.

D s
snippetusage

Required?Data TypeExample Value
YesString (column reference)myValues

dec_error_bound

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%). 

D s
snippetusage

Required?Data TypeExample Value
NoDecimal (literal)0.01

D s
snippetExamples

Example - Percentile functions

Include Page
EXAMPLE - Percentile Functions
EXAMPLE - Percentile Functions

D s also
labelaggregate