ulate across the columns.

        For `Series` this parameter is unused and defaults to 0.

    times : np.ndarray, Series, default None

        .. versionadded:: 1.1.0

        Only applicable to ``mean()``.

        Times corresponding to the observations. Must be monotonically increasing and
        ``datetime64[ns]`` dtype.

        If 1-D array like, a sequence with the same shape as the observations.

    method : str {'single', 'table'}, default 'single'
        .. versionadded:: 1.4.0

        Execute the rolling operation per single column or row (``'single'``)
        or over the entire object (``'table'``).

        This argument is only implemented when specifying ``engine='numba'``
        in the method call.

        Only applicable to ``mean()``

    Returns
    -------
    ``ExponentialMovingWindow`` subclass

    See Also
    --------
    rolling : Provides rolling window calculations.
    expanding : Provides expanding transformations.

    Notes
    -----
    See :ref:`Windowing Operations <window.exponentially_weighted>`
    for further usage details and examples.

    Examples
    --------
    >>> df = pd.DataFrame({'B': [0, 1, 2, np.nan, 4]})
    >>> df
         B
    0  0.0
    1  1.0
    2  2.0
    3  NaN
    4  4.0

    >>> df.ewm(com=0.5).mean()
              B
    0  0.000000
    1  0.750000
    2  1.615385
    3  1.615385
    4  3.670213
    >>> df.ewm(alpha=2 / 3).mean()
              B
    0  0.000000
    1  0.750000
    2  1.615385
    3  1.615385
    4  3.670213

    **adjust**

    >>> df.ewm(com=0.5, adjust=True).mean()
              B
    0  0.000000
    1  0.750000
    2  1.615385
    3  1.615385
    4  3.670213
    >>> df.ewm(com=0.5, adjust=False).mean()
              B
    0  0.000000
    1  0.666667
    2  1.555556
    3  1.555556
    4  3.650794

    **ignore_na**

    >>> df.ewm(com=0.5, ignore_na=True).mean()
              B
    0  0.000000
    1  0.750000
    2  1.615385
    3  1.615385
    4  3.225000
    >>> df.ewm(com=0.5, ignore_na=False).mean()
              B
    0  0.000000
    1  0.750000
    2  1.615385
    3  1.615385
    4  3.670213

    **times**

    Exponentially weighted mean with weights calculated with a timedelta ``halflife``
    relative to ``times``.

    >>> times = ['2020-01-01', '2020-01-03', '2020-01-10', '2020-01-15', '2020-01-17']
    >>> df.ewm(halflife='4 days', times=pd.DatetimeIndex(times)).mean()
              B
    0  0.000000
    1  0.585786
    2  1.523889
    3  1.523889
    4  3.233686
    )
Ú