def METHOD_NAME(self, pc):
    psi = - pc*1e-6
    if psi > self.psi_0:
        # saturated
        s1e = (1.0 - self.s_r) / (self.s_ft - self.s_r)
        se = s1e
    elif psi > self.psi_cap_ft_trans:
        # linear branch
        s1e = (1.0 - self.s_r) / (self.s_ft - self.s_r)
        se = s1e - (self.psi_0 - psi) / self.m_cap_star
    elif psi > self.psi_tlp:
        # turgor branch
        b = abs(self.pi_0) - psi - self.eps
        se = (-b + np.sqrt(b**2 + 4*self.eps*abs(self.pi_0))) / (2*self.eps)
    else:
        # embolism, turgor lost
        se = - abs(self.pi_0)/psi
    s = se * (self.s_ft - self.s_r) + self.s_r
    return s