Growth of exponential moving average.

    Parameters
    ----------
    eqdata : DataFrame
    span : int, optional
        Span for exponential moving average. Defaults to 20.
    outputcol : str, optional.
        Column to use for output. Defaults to 'EMA Growth'.
    selection : str, optional
        Column of eqdata on which to calculate ema growth. If
        `eqdata` has only 1 column, `selection` is ignored,
        and ema growth is calculated on that column. Defaults
        to 'Adj Close'.

    Returns
    ---------
    out : DataFrame
        Growth of exponential moving average from one day to next

def ema_growth(eqdata, **kwargs):
    """
    Growth of exponential moving average.

    Parameters
    ----------
    eqdata : DataFrame
    span : int, optional
        Span for exponential moving average. Defaults to 20.
    outputcol : str, optional.
        Column to use for output. Defaults to 'EMA Growth'.
    selection : str, optional
        Column of eqdata on which to calculate ema growth. If
        `eqdata` has only 1 column, `selection` is ignored,
        and ema growth is calculated on that column. Defaults
        to 'Adj Close'.

    Returns
    ---------
    out : DataFrame
        Growth of exponential moving average from one day to next
    """
    _growth_outputcol = kwargs.get('outputcol', 'EMA Growth')
    _ema_outputcol = 'EMA'
    kwargs['outputcol'] = _ema_outputcol
    _emadf = ema(eqdata, **kwargs)
    return simple.growth(_emadf, selection=_ema_outputcol, outputcol=_growth_outputcol)