def __init__(self,  local_error = 0.001, dz = 1e-5,
                 disable_Raman = False, disable_self_steepening = False,
                 suppress_iteration = True, USE_SIMPLE_RAMAN = False,
                 f_R = 0.18, f_R0 = 0.18, tau_1 = 0.0122, tau_2 = 0.0320):
        """
        This initialization function sets up the parameters of the SSFM.
        """
        self.iter = 0
        self.last_h = -1.0
        self.last_dir = 0.0
        self.eta = 5
        self.local_error = local_error
        self.method = SSFM.METHOD_RK4IP
        self.disable_Raman = disable_Raman
        self.disable_self_steepening = disable_self_steepening
        self.USE_SIMPLE_RAMAN = USE_SIMPLE_RAMAN

        # Raman fraction; may change depending upon which calculation method 
        # is used 
        self.f_R = f_R
        # The value for the old-style Raman response
        self.f_R0 = f_R0