pyspark.pandas.window.Expanding.mean¶
-
Expanding.
mean
() → FrameLike¶ Calculate the expanding mean of the values.
Note
the current implementation of this API uses Spark’s Window without specifying partition specification. This leads to move all data into single partition in single machine and could cause serious performance degradation. Avoid this method against very large dataset.
- Returns
- Series or DataFrame
Returned object type is determined by the caller of the expanding calculation.
See also
Series.expanding
Calling object with Series data.
DataFrame.expanding
Calling object with DataFrames.
Series.mean
Equivalent method for Series.
DataFrame.mean
Equivalent method for DataFrame.
Examples
The below examples will show expanding mean calculations with window sizes of two and three, respectively.
>>> s = ps.Series([1, 2, 3, 4]) >>> s.expanding(2).mean() 0 NaN 1 1.5 2 2.0 3 2.5 dtype: float64
>>> s.expanding(3).mean() 0 NaN 1 NaN 2 2.0 3 2.5 dtype: float64