def __init__(self, actions, discount, featureExtractor, explorationProb, stepSize, replay_memory_size, replay_memory_sample_size, num_static_target_update_steps, maxGradient, num_consecutive_random_actions): """ :note: please see parent class for params not described here """ super(QLearningReplayMemoryAlgorithm, self).__init__(actions, discount, featureExtractor, explorationProb, stepSize, maxGradient, num_consecutive_random_actions) self.replay_memory = ReplayMemory(replay_memory_size) self.sample_size = replay_memory_sample_size self.num_static_target_update_steps = num_static_target_update_steps self.static_target_weights = copy.deepcopy(self.weights) self.iterations = 0
def train(gamepath, n_episodes, display_screen, record_weights, reduce_exploration_prob_amount, n_frames_to_skip, exploration_prob, verbose, discount, learning_rate, load_weights, frozen_target_update_period, use_replay_mem): """ :description: trains an agent to play a game :type gamepath: string :param gamepath: path to the binary of the game to be played :type n_episodes: int :param n_episodes: number of episodes of the game on which to train display_screen : whether or not to display the screen of the game record_weights : whether or not to save the weights of the nextwork reduce_exploration_prob_amount : amount to reduce exploration prob each episode to not reduce exploration_prob set to 0 n_frames_to_skip : how frequently to determine a new action to use exploration_prob : probability of choosing a random action verbose : whether or not to print information about the run periodically discount : discount factor used in learning learning_rate : the scaling factor for the sgd update load_weights : whether or not to load weights for the network (set the files directly below) frozen_target_update_period : the number of episodes between reseting the target of the network """ # load the ale interface to interact with ale = ALEInterface() ale.setInt('random_seed', 42) # display/recording settings, doesn't seem to work currently recordings_dir = './recordings/breakout/' # previously "USE_SDL" if display_screen: if sys.platform == 'darwin': import pygame pygame.init() ale.setBool('sound', False) # Sound doesn't work on OSX #ale.setString("record_screen_dir", recordings_dir); elif sys.platform.startswith('linux'): ale.setBool('sound', True) ale.setBool('display_screen', True) ale.loadROM(gamepath) ale.setInt("frame_skip", n_frames_to_skip) # real actions for breakout are [0,1,3,4] real_actions = ale.getMinimalActionSet() # use a list of actions [0,1,2,3] to index into the array of real actions actions = np.arange(len(real_actions)) # these theano variables are used to define the symbolic input of the network features = T.dvector('features') action = T.lscalar('action') reward = T.dscalar('reward') next_features = T.dvector('next_features') # load weights by file name # currently must be loaded by individual hidden layers if load_weights: hidden_layer_1 = file_utils.load_model('weights/hidden0_replay.pkl') hidden_layer_2 = file_utils.load_model('weights/hidden1_replay.pkl') else: # defining the hidden layer network structure # the n_hid of a prior layer must equal the n_vis of a subsequent layer # for q-learning the output layer must be of len(actions) hidden_layer_1 = HiddenLayer(n_vis=NNET_INPUT_DIMENSION, n_hid=NNET_INPUT_DIMENSION, layer_name='hidden1', activation='relu') hidden_layer_2 = HiddenLayer(n_vis=NNET_INPUT_DIMENSION, n_hid=NNET_INPUT_DIMENSION, layer_name='hidden2', activation='relu') hidden_layer_3 = HiddenLayer(n_vis=NNET_INPUT_DIMENSION, n_hid=len(actions), layer_name='hidden3', activation='relu') # the output layer is currently necessary when using tanh units in the # hidden layer in order to prevent a theano warning # currently the relu unit setting of the hidden and output layers is leaky w/ alpha=0.01 output_layer = OutputLayer(layer_name='output', activation='relu') # pass a list of layers to the constructor of the network (here called "mlp") layers = [hidden_layer_1, hidden_layer_2, hidden_layer_3, output_layer] qnetwork = QNetwork(layers, discount=discount, learning_rate=learning_rate) # this call gets the symbolic output of the network # along with the parameter updates expected loss, updates = qnetwork.get_loss_and_updates(features, action, reward, next_features) # this defines the theano symbolic function used to train the network # 1st argument is a list of inputs, here the symbolic variables above # 2nd argument is the symbolic output expected # 3rd argument is the dictionary of parameter updates # 4th argument is the compilation mode train_model = theano.function( [theano.Param(features, default=np.zeros(NNET_INPUT_DIMENSION)), theano.Param(action, default=0), theano.Param(reward, default=0), theano.Param(next_features, default=np.zeros(NNET_INPUT_DIMENSION))], outputs=loss, updates=updates, mode='FAST_RUN') sym_action = qnetwork.get_action(features) get_action = theano.function([features], sym_action) # some containers for collecting information about the training processes rewards = [] losses = [] best_reward = 4 sequence_examples = [] sampled_examples = [] # the preprocessor and feature extractor to use preprocessor = screen_utils.RGBScreenPreprocessor() feature_extractor = feature_extractors.NNetOpenCVBoundingBoxExtractor(max_features=MAX_FEATURES) if use_replay_mem: replay_mem = ReplayMemory() # main training loop, each episode is a full playthrough of the game for episode in xrange(n_episodes): # this implements the frozen target component of the network # by setting the frozen layers of the network to a copy of the current layers if episode % frozen_target_update_period == 0: qnetwork.frozen_layers = copy.deepcopy(qnetwork.layers) # some variables for collecting information about this particular run of the game total_reward = 0 action = 1 counter = 0 reward = 0 loss = 0 previous_param_0 = None # lives here is used for the reward heuristic of subtracting 1 from the reward # when we lose a life. currently commented out this functionality because # i think it might not be helpful. lives = ale.lives() # the initial state of the screen and state screen = np.zeros((preprocessor.dim, preprocessor.dim, preprocessor.channels)) state = { "screen" : screen, "objects" : None, "prev_objects": None, "features": np.zeros(MAX_FEATURES)} # start the actual play through of the game while not ale.game_over(): counter += 1 # get the current features, which is the representation of the state provided to # the "agent" (here just the network directly) features = state["features"] # epsilon greedy action selection (note that exploration_prob is reduced by # reduce_exploration_prob_amount after every game) if random.random() < exploration_prob: action = random.choice(actions) else: # to choose an action from the network, we fprop # the current state and take the argmax of the output # layer (i.e., the action that corresponds to the # maximum q value) action = get_action(features) # take the action and receive the reward reward += ale.act(real_actions[action]) # this is commented out because i think it might not be helpful if ale.lives() < lives: lives = ale.lives() reward -= 1 # get the next screen, preprocess it, initialize the next state next_screen = ale.getScreenRGB() next_screen = preprocessor.preprocess(next_screen) next_state = {"screen": next_screen, "objects": None, "prev_objects": state["objects"]} # get the features for the next state next_features = feature_extractor(next_state, action=None) if use_replay_mem: sars_tuple = (features, action, reward, next_features) replay_mem.store(sars_tuple) num_samples = 5 if replay_mem.isFull() else 1 for i in range(0, num_samples): random_train_tuple = replay_mem.sample() loss += train_model(*random_train_tuple) # collect for pca sequence_examples.append(list(sars_tuple[0]) + [sars_tuple[1]] \ + [sars_tuple[2]] + sars_tuple[3]) sequence_examples = sequence_examples[-100:] sampled_examples.append(list(random_train_tuple[0]) + [random_train_tuple[1]] \ + [random_train_tuple[2]] + random_train_tuple[3]) sampled_examples = sampled_examples[-100:] else: # call the train model function loss += train_model(features, action, reward, next_features) # prepare for the next loop through the game next_state["features"] = next_features state = next_state # weird counter value to avoid interaction with any other counter # loop that might be added, not necessary right now if verbose and counter % PRINT_TRAINING_INFO_PERIOD == 0: print('*' * 15 + ' training information ' + '*' * 15) print('episode: {}'.format(episode)) print('reward: \t{}'.format(reward)) print('avg reward: \t{}'.format(np.mean(rewards))) print 'avg reward (last 25): \t{}'.format(np.mean(rewards[-NUM_EPISODES_AVERAGE_REWARD_OVER:])) print('action: \t{}'.format(real_actions[action])) print('exploration prob: {}'.format(exploration_prob)) param_info = [(p.eval(), p.name) for p in qnetwork.get_params()] for index, (val, name) in enumerate(param_info): if previous_param_0 is None and index == 0: previous_param_0 = val print('parameter {} value: \n{}'.format(name, val)) if index == 0: diff = val - previous_param_0 print('difference from previous param {}: \n{}'.format(name, diff)) print('features: \t{}'.format(features)) print('next_features: \t{}'.format(next_features)) scaled_sequence = preprocessing.scale(np.array(sequence_examples)) scaled_sampled = preprocessing.scale(np.array(sampled_examples)) pca = PCA() _ = pca.fit_transform(scaled_sequence) print('variance explained by first component for sequence: {}%'.format(pca. \ explained_variance_ratio_[0] * 100)) _ = pca.fit_transform(scaled_sampled) print('variance explained by first component for sampled: {}%'.format(pca. \ explained_variance_ratio_[0] * 100)) print('*' * 52) print('\n') # collect info and total reward and also reset the reward to 0 if we reach this point total_reward += reward reward = 0 # collect stats from this game run losses.append(loss) rewards.append(total_reward) # if we got a best reward, inform the user if total_reward > best_reward: best_reward = total_reward print("best reward!: {}".format(total_reward)) # record the weights if record_weights=True # must record the weights of the indiviual layers # only save hidden layers b/c output layer does not have weights if episode != 0 and episode % RECORD_WEIGHTS_PERIOD == 0 and record_weights: file_utils.save_rewards(rewards) file_utils.save_model(qnetwork.layers[0], 'weights/hidden0_{}.pkl'.format(episode)) file_utils.save_model(qnetwork.layers[1], 'weights/hidden1_{}.pkl'.format(episode)) # reduce exploration policy over time if exploration_prob > MINIMUM_EXPLORATION_EPSILON: exploration_prob -= reduce_exploration_prob_amount # inform user of how the episode went and reset the game print('episode: {} ended with score: {}\tloss: {}'.format(episode, rewards[-1], losses[-1])) ale.reset_game() # return the list of rewards attained return rewards