def psq2(d1, d2):
    """Compute the PSQ2 measure.

    Args:
        d1 (np.ndarray): The first distribution.
        d2 (np.ndarray): The second distribution.
    """
    d1, d2 = flatten(d1), flatten(d2)

    def f(p):
        return sum((p ** 2) * np.nan_to_num(np.log(p * len(p))))

    return abs(f(d1) - f(d2))
Compute the PSQ2 measure.

    Args:
        d1 (np.ndarray): The first distribution.
        d2 (np.ndarray): The second distribution.