def init_demo_buffer()

in baselines/her/ddpg.py [0:0]


    def init_demo_buffer(self, demoDataFile, update_stats=True): #function that initializes the demo buffer

        demoData = np.load(demoDataFile) #load the demonstration data from data file
        info_keys = [key.replace('info_', '') for key in self.input_dims.keys() if key.startswith('info_')]
        info_values = [np.empty((self.T - 1, 1, self.input_dims['info_' + key]), np.float32) for key in info_keys]

        demo_data_obs = demoData['obs']
        demo_data_acs = demoData['acs']
        demo_data_info = demoData['info']

        for epsd in range(self.num_demo): # we initialize the whole demo buffer at the start of the training
            obs, acts, goals, achieved_goals = [], [] ,[] ,[]
            i = 0
            for transition in range(self.T - 1):
                obs.append([demo_data_obs[epsd][transition].get('observation')])
                acts.append([demo_data_acs[epsd][transition]])
                goals.append([demo_data_obs[epsd][transition].get('desired_goal')])
                achieved_goals.append([demo_data_obs[epsd][transition].get('achieved_goal')])
                for idx, key in enumerate(info_keys):
                    info_values[idx][transition, i] = demo_data_info[epsd][transition][key]


            obs.append([demo_data_obs[epsd][self.T - 1].get('observation')])
            achieved_goals.append([demo_data_obs[epsd][self.T - 1].get('achieved_goal')])

            episode = dict(o=obs,
                           u=acts,
                           g=goals,
                           ag=achieved_goals)
            for key, value in zip(info_keys, info_values):
                episode['info_{}'.format(key)] = value

            episode = convert_episode_to_batch_major(episode)
            global DEMO_BUFFER
            DEMO_BUFFER.store_episode(episode) # create the observation dict and append them into the demonstration buffer
            logger.debug("Demo buffer size currently ", DEMO_BUFFER.get_current_size()) #print out the demonstration buffer size

            if update_stats:
                # add transitions to normalizer to normalize the demo data as well
                episode['o_2'] = episode['o'][:, 1:, :]
                episode['ag_2'] = episode['ag'][:, 1:, :]
                num_normalizing_transitions = transitions_in_episode_batch(episode)
                transitions = self.sample_transitions(episode, num_normalizing_transitions)

                o, g, ag = transitions['o'], transitions['g'], transitions['ag']
                transitions['o'], transitions['g'] = self._preprocess_og(o, ag, g)
                # No need to preprocess the o_2 and g_2 since this is only used for stats

                self.o_stats.update(transitions['o'])
                self.g_stats.update(transitions['g'])

                self.o_stats.recompute_stats()
                self.g_stats.recompute_stats()
            episode.clear()

        logger.info("Demo buffer size: ", DEMO_BUFFER.get_current_size()) #print out the demonstration buffer size