structs.py 文件源码

def ecc(self, val):
        '''
        We need to update the time of pericenter passage whenever the
        eccentricty, longitude of pericenter, period, or time of transit
        changes. See the appendix in Shields et al. (2016).

        '''

        self._ecc = val
        fi = (3 * np.pi / 2.) - self._w
        self.tperi0 = self.t0 + (self.per * np.sqrt(1. - self.ecc * self.ecc) /
                     (2. * np.pi) * (self.ecc * np.sin(fi) /
                     (1. + self.ecc * np.cos(fi)) - 2.
                     / np.sqrt(1. - self.ecc * self.ecc)
                     * np.arctan2(np.sqrt(1. - self.ecc * self.ecc)
                     * np.tan(fi/2.), 1. + self.ecc)))