code: def H7(self):
          "Sum variance (error in Haralick's original paper here)."
          h6 = np.tile(self.H6(), (self.rlevels2.shape[1], 1)).transpose()
          return (((self.rlevels2 + 2) - h6) ** 2 * self.p_xplusy).sum(1f H7(self):
          "Sum variance (error in Haralick's original paper here)."
          h6 = np.tile(self.H6(), (self.rlevels2.shape[1], 1)).transpose()
          return (((self.rlevels2 + 2) - h6) ** 2 * self.p_xplusy).sum(1)
docs: Sum variance (error in Haralick's original paper here).