pipes.py 文件源码

def _f4(self, z):
        """
        Calculate function f4 from Hellstrom (1991)
        """
        A = self._delta*self._beta1 + self._beta2*self._beta12/self._gamma
        f4 = np.exp(self._beta*z) \
            * (self._beta1*np.cosh(self._gamma*z) - A*np.sinh(self._gamma*z))
        return f4