pandas.core.window.expanding.Expanding.sem¶

Expanding.sem(ddof=1, *args, **kwargs)[source]¶

Compute expanding standard error of mean.

Parameters

ddofint, 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: Returned object type is determined by the caller of the expanding calculation.

See also

Notes

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

Examples

>>> s = pd.Series([0, 1, 2, 3])
>>> s.rolling(2, min_periods=1).sem()
0         NaN
1    0.707107
2    0.707107
3    0.707107
dtype: float64

>>> s.expanding().sem()
0         NaN
1    0.707107
2    0.707107
3    0.745356
dtype: float64