def BED_calc0( dose, ab,sparing = 1):
    """
    calculates the BED for a specific dose

    Parameters
    ----------
    dose : float
        physical dose to be delivered.
    ab : float
        alpha-beta ratio of tissue.
    sparing : float, optional
        sparing factor. The default is 1 (tumor).

    Returns
    -------
    BED : float
        BED to be delivered based on dose, sparing factor and alpha-beta ratio.

    """
    BED = sparing*dose*(1+(sparing*dose)/ab)
    return BED