import cmath


def average_radians(list_of_radians):
    """
    Return average of a list of angles, in radians, and it's amplitude.

    We calculate a set of vectors for each angle, using a fixed distance.
    Add up the sum of the x, y of the resulting vectors.
    Work back to an angle + get a magnitude.

    :param list_of_radians:
    :return:
    """
    vectors = [cmath.rect(1, angle) if angle is not None else cmath.rect(0, 0)
               # length 1 for each vector; or 0,0 for null (stopped)
               for angle in list_of_radians]

    vector_sum = sum(vectors)
    return cmath.phase(vector_sum), abs(vector_sum)