def contraction_round_Miller(Di1, Di2, rc):
    r'''Returns loss coefficient for any round edged pipe contraction
    using the method of Miller [1]_. This method uses a spline fit to a graph
    with area ratios 0 to 1, and radius ratios (rc/Di2) from 0.1 to 0.

    Parameters
    ----------
    Di1 : float
        Inside diameter of original pipe, [m]
    Di2 : float
        Inside diameter of following pipe, [m]
    rc : float
        Radius of curvature of the contraction, [m]

    Returns
    -------
    K : float
        Loss coefficient in terms of the following pipe, [-]

    Notes
    -----
    This method normally gives lower losses than the Rennels formulation.

    Examples
    --------
    >>> contraction_round_Miller(Di1=1, Di2=0.4, rc=0.04)
    0.08565953051298639

    References
    ----------
    .. [1] Miller, Donald S. Internal Flow Systems: Design and Performance
       Prediction. Gulf Publishing Company, 1990.
    '''
    A_ratio = Di2*Di2/(Di1*Di1)
    radius_ratio = rc/Di2
    if radius_ratio > 0.1:
        radius_ratio = 0.1
    Ks = float(bisplev(A_ratio, radius_ratio, tck_contraction_abrupt_Miller))
    # For some near-1 ratios, can get negative Ks due to the spline.
    if Ks < 0.0:
        Ks = 0.0
    return Ks