pipes.py 文件源码

def _F4(self, z):
        """
        Calculate integral of function f4 from Hellstrom (1991)
        """
        A = self._delta*self._beta1 + self._beta2*self._beta12/self._gamma
        C = self._beta1*self._beta + A*self._gamma
        S = - (self._beta1*self._gamma + self._beta*A)
        denom = (self._beta**2 - self._gamma**2)
        F4 = np.exp(self._beta*z) / denom \
            * (C*np.cosh(self._gamma*z) + S*np.sinh(self._gamma*z))
        return F4