pandas.core.window.rolling.Rolling.std¶
- Rolling.std(ddof=1, *args, **kwargs)[source]¶
Calculate the rolling standard deviation.
- Parameters
- ddofint, default 1
Delta Degrees of Freedom. The divisor used in calculations is
N - ddof
, whereN
represents the number of elements.- *args
For NumPy compatibility and will not have an effect on the result.
- **kwargs
For NumPy compatibility and will not have an effect on the result.
- Returns
- Series or DataFrame
Return type is the same as the original object.
See also
numpy.std
Equivalent method for NumPy array.
pandas.Series.rolling
Calling rolling with Series data.
pandas.DataFrame.rolling
Calling rolling with DataFrames.
pandas.Series.std
Aggregating std for Series.
pandas.DataFrame.std
Aggregating std for DataFrame.
Notes
The default
ddof
of 1 used inSeries.std()
is different than the defaultddof
of 0 innumpy.std()
.A minimum of one period is required for the rolling calculation.
The implementation is susceptible to floating point imprecision as shown in the example below.
Examples
>>> s = pd.Series([5, 5, 6, 7, 5, 5, 5]) >>> s.rolling(3).std() 0 NaN 1 NaN 2 5.773503e-01 3 1.000000e+00 4 1.000000e+00 5 1.154701e+00 6 2.580957e-08 dtype: float64