code: def H3(self):
          "Correlation."
          multiplied = np.dot(self.levels[:, np.newaxis] + 1,
                              self.levels[np.newaxis] + 1)
          repeated = np.tile(multiplied[np.newaxis], (self.nobjects, 1, 1))
          summed = (repeated * self.P).sum(2).sum(1)
          h3 = (summed - self.mux * self.muy) / (self.sigmax * self.sigmay)
          h3[np.isinf(h3)] = 0
          return hf H3(self):
          "Correlation."
          multiplied = np.dot(self.levels[:, np.newaxis] + 1,
                              self.levels[np.newaxis] + 1)
          repeated = np.tile(multiplied[np.newaxis], (self.nobjects, 1, 1))
          summed = (repeated * self.P).sum(2).sum(1)
          h3 = (summed - self.mux * self.muy) / (self.sigmax * self.sigmay)
          h3[np.isinf(h3)] = 0
          return h3
docs: Correlation.