code: def predicted_obs_vec(self):
          '''The predicted observation vector
  
          The observation vector for the next step in the filter.
          '''
          if not self.has_cached_obs_vec:
              self.obs_vec = dot_n(
                  self.observation_matrix,
                  self.predicted_state_vec[:,:,np.newaxis])[:,:,0]
          return self.obs_vef predicted_obs_vec(self):
          '''The predicted observation vector
  
          The observation vector for the next step in the filter.
          '''
          if not self.has_cached_obs_vec:
              self.obs_vec = dot_n(
                  self.observation_matrix,
                  self.predicted_state_vec[:,:,np.newaxis])[:,:,0]
          return self.obs_vec
docs: The predicted observation vector
  
          The observation vector for the next step in the filter.