pyspark.sql.functions.kll_sketch_get_n_double#

pyspark.sql.functions.kll_sketch_get_n_double(col)[source]#

Returns the number of items collected in the KLL double sketch.

Added in version 4.1.0.

Parameters:

colColumn or column name: The KLL double sketch binary representation. A column that evaluates to a binary.

Returns:

Column: The count of items in the sketch. Returns a column that evaluates to a long.

Examples

>>> 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_n_double("sketch")).show()
+-------------------------------+
|kll_sketch_get_n_double(sketch)|
+-------------------------------+
|                              5|
+-------------------------------+