nxcals.api.extraction.data.builders.DataFrame.cov

DataFrame.cov(col1: str, col2: str) → float

Calculate the sample covariance for the given columns, specified by their names, as a double value. DataFrame.cov() and DataFrameStatFunctions.cov() are aliases.

New in version 1.4.0.

Changed in version 3.4.0: Supports Spark Connect.

Parameters:

  • col1 (str) – The name of the first column

  • col2 (str) – The name of the second column

Returns:

Covariance of two columns.

Return type:

float

Examples

>>> df = spark.createDataFrame([(1, 12), (10, 1), (19, 8)], ["c1", "c2"])
>>> df.cov("c1", "c2")
-18.0
>>> df = spark.createDataFrame([(11, 12), (10, 11), (9, 10)], ["small", "bigger"])
>>> df.cov("small", "bigger")
1.0