def mirbi(b11, b12):
    """
    Mid Infrared Burned Index (Trigg and Flasse, 2001).

    .. math:: MIRBI = 10 * b12 - 9.8 * b11 + 2

    :param b11: SWIR 1.
    :type b11: numpy.ndarray or float
    :param b12: SWIR 2.
    :type b12: numpy.ndarray or float

    :returns MIRBI: Index value

    .. Tip::

        Trigg, S., Flasse, S. 2001. An evaluation of different bi-spectral \
        spaces for discriminating burned shrub-savannah. International \
        Journal of Remote Sensing 22(13), 2641-2647. \
        doi:10.1080/01431160110053185.
    """

    MIRBI = 10 * b12 - 9.8 * b11 + 2
    return MIRBI