code: def get_cosmo(self, Dd, Ds_Dds):
          
          if not hasattr(self, '_f_H0') or not hasattr(self, '_f_omega_m'):
              self._make_interpolation()
          H0 = self._f_H0(Dd, Ds_Dds)
          print(H0, 'H0')
          omega_m = self._f_omega_m(Dd, Ds_Dds)
          Dd_new, Ds_Dds_new = self.cosmo2Dd_Ds_Dds(H0[0], omega_m[0])
          if abs(Dd - Dd_new)/Dd > 0.01 or abs(Ds_Dds - Ds_Dds_new)/Ds_Dds > 0.01:
              return [-1], [-1]
          else:
              return H0[0], omega_m[0]
docs: return the values of H0 and omega_m computed with an interpolation
          :param Dd: flat
          :param Ds_Dds: float
          :return: