def cired_re(b4, b5, b8, a=0.7):
    """
    Red and Red-edge Modified Chlorophyll Index (Xie et al. 2018).

    .. math:: CIREDRE = (b8 / (a * b4 + (1 - a) * b5)) - 1

    :param b4: Red.
    :type b4: numpy.ndarray or float
    :param b5: Red-edge 1.
    :type b5: numpy.ndarray or float
    :param b8: NIR.
    :type b8: numpy.ndarray or float
    :param a: parameter.
    :type a: float

    :returns CIREDRE: Index value

    .. Tip::

        Xie, Q., Dash, J., Huang, W., Peng, D., Qin, Q., Mortimer, \
        H., ... Dong, Y. 2018. Vegetation indices combining the red \
        and red-edge spectral information for leaf area index retrieval. \
        IEEE Journal of Selected Topics in Applied Earth Observations \
        and Remote Sensing 11(5), 1482-1493. doi:10.1109/JSTARS.2018.2813281.
    """

    CIREDRE = (b8 / (a * b4 + (1 - a) * b5)) - 1
    return CIREDRE