Table Of Contents

Search

Enter search terms or a module, class or function name.

pandas.core.window.Rolling.std

Rolling.std(ddof=1, *args, **kwargs)[source]

Calculate rolling standard deviation.

Normalized by N-1 by default. This can be changed using the ddof argument.

Parameters:

ddof : int, default 1

Delta Degrees of Freedom. The divisor used in calculations is N - ddof, where N represents the number of elements.

*args, **kwargs

For NumPy compatibility. No additional arguments are used.

Returns:

Series or DataFrame

Returns the same object type as the caller of the rolling calculation.

See also

Series.rolling
Calling object with Series data
DataFrame.rolling
Calling object with DataFrames
Series.std
Equivalent method for Series
DataFrame.std
Equivalent method for DataFrame
numpy.std
Equivalent method for Numpy array

Notes

The default ddof of 1 used in Series.std is different than the default ddof of 0 in numpy.std.

A minimum of one period is required for the rolling calculation.

Examples

>>> s = pd.Series([5, 5, 6, 7, 5, 5, 5])
>>> s.rolling(3).std()
0         NaN
1         NaN
2    0.577350
3    1.000000
4    1.000000
5    1.154701
6    0.000000
dtype: float64
>>> s.expanding(3).std()
0         NaN
1         NaN
2    0.577350
3    0.957427
4    0.894427
5    0.836660
6    0.786796
dtype: float64
Scroll To Top