def METHOD_NAME(x, y, z, earth_radius):
    """
    Cartesian transect points to great-circle distance
    Parameters
    ----------
    x : numpy.ndarray
        The Cartesian x coordinate of a transect
    y : numpy.ndarray
        The Cartesian y coordinate of the transect
    z : numpy.ndarray
        The Cartesian z coordinate of the transect
    earth_radius : float
        The radius of the earth
    Returns
    -------
    distance : numpy.ndarray
        The distance along the transect
    """
    distance = numpy.zeros(x.shape)
    for segIndex in range(len(x)-1):
        transectv0 = Vector(x[segIndex], y[segIndex], z[segIndex])
        transectv1 = Vector(x[segIndex+1], y[segIndex+1], z[segIndex+1])
        distance[segIndex+1] = distance[segIndex] + \
            earth_radius*transectv0.angular_distance(transectv1)
    return distance