def _compute_term_4(self, C, mag, R):
        """
        (a16 + a17.*M + a18.*M.*M + a19.*M.*M.*M).*(d(r).^3)
        """
        return (
            (C['a16'] + C['a17'] * mag + C['a18'] * np.power(mag, 2) +
             C['a19'] * np.power(mag, 3)) * np.power(R, 3)
        )
def _compute_term_4 ( self , C , mag , R ) : return ( ( C [ 'a16' ] + C [ 'a17' ] * mag + C [ 'a18' ] * np . power ( mag , 2 ) + C [ 'a19' ] * np . power ( mag , 3 ) ) * np . power ( R , 3 ) )
(a16 + a17.*M + a18.*M.*M + a19.*M.*M.*M).*(d(r).^3)