likelihood.py 文件源码

def design_matrix(nonlinear_p, data, joker_params):
    """

    Parameters
    ----------
    nonlinear_p : array_like
        Array of non-linear parameter values. For the default case,
        these are P (period, day), phi0 (phase at pericenter, rad),
        ecc (eccentricity), omega (argument of perihelion, rad).
        May also contain log(jitter^2) as the last index.
    data : `~thejoker.data.RVData`
        The observations.
    joker_params : `~thejoker.sampler.params.JokerParams`
        The specification of parameters to infer with The Joker.

    Returns
    -------
    A : `numpy.ndarray`
        The design matrix with shape ``(n_times, n_params)``.

    """
    P, phi0, ecc, omega = nonlinear_p[:4] # we don't need the jitter here

    # phi0 now is implicitly relative to data.t_offset, not mjd=0
    t = data._t_bmjd
    zdot = rv_from_elements(times=t, P=P, K=1., e=ecc,
                            omega=omega, phi0=phi0,
                            anomaly_tol=joker_params.anomaly_tol)

    # TODO: right now, we only support a single, global velocity trend!
    A1 = np.vander(t, N=joker_params._n_trend, increasing=True)
    A = np.hstack((zdot[:,None], A1))

    return A