def results(self, Pc):
        r
        Psatn = self['pore.invasion_pressure'] <= Pc
        Tsatn = self['throat.invasion_pressure'] <= Pc
        inv_phase = {}
        inv_phase['pore.occupancy'] = sp.array(Psatn, dtype=float)
        inv_phase['throat.occupancy'] = sp.array(Tsatn, dtype=float)
        return inv_phase