kll_sketch_get_quantile_double

Extracts a quantile value from a KLL double sketch given an input rank value. The rank can be a single value or an array.

Syntax

Python

from pyspark.sql import functions as sf

sf.kll_sketch_get_quantile_double(sketch, rank)

Parameters

Parameter	Type	Description
sketch	pyspark.sql.Column or str	The KLL double sketch binary representation.
rank	pyspark.sql.Column or str	The rank value(s) to extract (between 0.0 and 1.0).

Returns

pyspark.sql.Column: The quantile value(s).

Examples

Example 1: Get quantile from KLL double sketch

Python

from pyspark.sql import functions as sf
df = spark.createDataFrame([1.0,2.0,3.0,4.0,5.0], "DOUBLE")
sketch_df = df.agg(sf.kll_sketch_agg_double("value").alias("sketch"))
sketch_df.select(sf.kll_sketch_get_quantile_double("sketch", sf.lit(0.5))).show()

Output

+-------------------------------------------+
|kll_sketch_get_quantile_double(sketch, 0.5)|
+-------------------------------------------+
|                                        3.0|
+-------------------------------------------+