def bayes_factor(model_1, model_2):
    """
    Use the `Bayes factor`_ to compare two models. Using Table from `Kass and Raftery`_ to compare.

    Args:
        model_1 (:py:class:`uncertainties.core.Variable` or :py:attr:`float`): ln evidence for model 1.
        model_2 (:py:class:`uncertainties.core.Variable` or :py:attr:`float`): ln evidence for model 2.

    Return:
        :py:class:`uncertainties.core.Variable` or :py:attr:`float`: 2ln(B), where B is the Bayes Factor between the two models.

    .. _Bayes factor: https://en.wikipedia.org/wiki/Bayes_factor
    .. _Kass and Raftery: https://www.colorado.edu/amath/sites/default/files/attached-files/kassraftery95.pdf
    """
    return 2 * (model_1 - model_2)