def nu_to_D(nu):
    """Parabolic eccentric anomaly from true anomaly.

    Parameters
    ----------
    nu : ~astropy.units.Quantity
        True anomaly.

    Returns
    -------
    D : ~astropy.units.Quantity
        Hyperbolic eccentric anomaly.

    Notes
    -----
    Taken from Farnocchia, Davide, Davide Bracali Cioci, and Andrea Milani.
    "Robust resolution of Kepler’s equation in all eccentricity regimes."
    Celestial Mechanics and Dynamical Astronomy 116, no. 1 (2013): 21-34.
    """
    return (nu_to_D_fast(nu.to_value(u.rad)) * u.rad).to(nu.unit)