code: def third_parameter(self, singular_value):
          
          if self.__need_omitted is False:
              return 0.0
          self.log("calc third term parameter @" + str(singular_value))
          GZo = self.G(singular_value) * self.omitted_jco
          result = GZo * self.omitted_parcov * GZo.T
          self.log("calc third term parameter @" + str(singular_value))
          return result
docs: get the omitted parameter contribution to parameter error variance
               at a singular value (G * omitted_jco * Sigma_(omitted_pars) * omitted_jco^T * G^T)
  
          Parameters
          ----------
          singular_value : int
              singular value to calc third term at
  
          Returns
          -------
          third_parameter : pyemu.Cov
              0.0 if need_omitted is False