code: def reconstruct(self, X=None):
          
  
          if X is None:
              X = self.X
          Xf = sl.rfftn(X, None, self.cri.axisN)
          Sf = np.sum(self.Df * Xf, axis=self.cri.axisM)
          return sl.irfftn(Sf, self.cri.Nv, self.cri.axisN)
docs: Reconstruct representation.