This is the python source code of RL_brainDQN.py for post Reinforcement Learning Python DQN Application for Resource Allocation
""" This part of code is the DQN brain, which is a brain of the agent. All decisions are made in here. Using Tensorflow to build the neural network. (MIT license) """ import numpy as np import tensorflow as tf np.random.seed(1) tf.set_random_seed(1) # Deep Q Network off-policy class DeepQNetwork: def __init__( self, n_actions, n_features, learning_rate=0.01, reward_decay=0.9, e_greedy=0.9, replace_target_iter=300, memory_size=500, batch_size=32, e_greedy_increment=None, output_graph=True, ): self.n_actions = n_actions self.n_features = n_features self.lr = learning_rate self.gamma = reward_decay self.epsilon_max = e_greedy self.replace_target_iter = replace_target_iter self.memory_size = memory_size self.batch_size = batch_size self.epsilon_increment = e_greedy_increment self.epsilon = 0 if e_greedy_increment is not None else self.epsilon_max # total learning step self.learn_step_counter = 0 # initialize zero memory [s, a, r, s_] self.memory = np.zeros((self.memory_size, n_features * 2 + 2)) # consist of [target_net, evaluate_net] self._build_net() t_params = tf.get_collection('target_net_params') e_params = tf.get_collection('eval_net_params') self.replace_target_op = [tf.assign(t, e) for t, e in zip(t_params, e_params)] self.sess = tf.Session() if output_graph: # $ tensorboard --logdir=logs # tf.train.SummaryWriter soon be deprecated, use following tf.summary.FileWriter("logs/", self.sess.graph) self.sess.run(tf.global_variables_initializer()) self.cost_his = [] def _build_net(self): # ------------------ build evaluate_net ------------------ self.s = tf.placeholder(tf.float32, [None, self.n_features], name='s') # input self.q_target = tf.placeholder(tf.float32, [None, self.n_actions], name='Q_target') # for calculating loss with tf.variable_scope('eval_net'): # c_names(collections_names) are the collections to store variables c_names, n_l1, w_initializer, b_initializer = \ ['eval_net_params', tf.GraphKeys.GLOBAL_VARIABLES], 10, \ tf.random_normal_initializer(0., 0.3), tf.constant_initializer(0.1) # config of layers # first layer. collections is used later when assign to target net with tf.variable_scope('l1'): w1 = tf.get_variable('w1', [self.n_features, n_l1], initializer=w_initializer, collections=c_names) b1 = tf.get_variable('b1', [1, n_l1], initializer=b_initializer, collections=c_names) l1 = tf.nn.relu(tf.matmul(self.s, w1) + b1) # second layer. collections is used later when assign to target net with tf.variable_scope('l2'): w2 = tf.get_variable('w2', [n_l1, self.n_actions], initializer=w_initializer, collections=c_names) b2 = tf.get_variable('b2', [1, self.n_actions], initializer=b_initializer, collections=c_names) self.q_eval = tf.matmul(l1, w2) + b2 with tf.variable_scope('loss'): self.loss = tf.reduce_mean(tf.squared_difference(self.q_target, self.q_eval)) with tf.variable_scope('train'): self._train_op = tf.train.RMSPropOptimizer(self.lr).minimize(self.loss) # ------------------ build target_net ------------------ self.s_ = tf.placeholder(tf.float32, [None, self.n_features], name='s_') # input with tf.variable_scope('target_net'): # c_names(collections_names) are the collections to store variables c_names = ['target_net_params', tf.GraphKeys.GLOBAL_VARIABLES] # first layer. collections is used later when assign to target net with tf.variable_scope('l1'): w1 = tf.get_variable('w1', [self.n_features, n_l1], initializer=w_initializer, collections=c_names) b1 = tf.get_variable('b1', [1, n_l1], initializer=b_initializer, collections=c_names) l1 = tf.nn.relu(tf.matmul(self.s_, w1) + b1) # second layer. collections is used later when assign to target net with tf.variable_scope('l2'): w2 = tf.get_variable('w2', [n_l1, self.n_actions], initializer=w_initializer, collections=c_names) b2 = tf.get_variable('b2', [1, self.n_actions], initializer=b_initializer, collections=c_names) self.q_next = tf.matmul(l1, w2) + b2 def store_transition(self, s, a, r, s_): if not hasattr(self, 'memory_counter'): self.memory_counter = 0 transition = np.hstack((s, [a, r], s_)) # replace the old memory with new memory index = self.memory_counter % self.memory_size self.memory[index, :] = transition self.memory_counter += 1 def choose_action(self, observation): # to have batch dimension when feed into tf placeholder observation = np.array(observation) observation = observation[np.newaxis,: ] if np.random.uniform() < self.epsilon: # forward feed the observation and get q value for every actions actions_value = self.sess.run(self.q_eval, feed_dict={self.s: observation}) action = np.argmax(actions_value) else: action = np.random.randint(0, self.n_actions) return action def learn(self): # check to replace target parameters if self.learn_step_counter % self.replace_target_iter == 0: self.sess.run(self.replace_target_op) print('\ntarget_params_replaced\n') # sample batch memory from all memory if self.memory_counter > self.memory_size: sample_index = np.random.choice(self.memory_size, size=self.batch_size) else: sample_index = np.random.choice(self.memory_counter, size=self.batch_size) batch_memory = self.memory[sample_index, :] q_next, q_eval = self.sess.run( [self.q_next, self.q_eval], feed_dict={ self.s_: batch_memory[:, -self.n_features:], # fixed params self.s: batch_memory[:, :self.n_features], # newest params }) # change q_target w.r.t q_eval's action q_target = q_eval.copy() batch_index = np.arange(self.batch_size, dtype=np.int32) eval_act_index = batch_memory[:, self.n_features].astype(int) reward = batch_memory[:, self.n_features + 1] q_target[batch_index, eval_act_index] = reward + self.gamma * np.max(q_next, axis=1) # train eval network _, self.cost = self.sess.run([self._train_op, self.loss], feed_dict={self.s: batch_memory[:, :self.n_features], self.q_target: q_target}) self.cost_his.append(self.cost) # increasing epsilon self.epsilon = self.epsilon + self.epsilon_increment if self.epsilon < self.epsilon_max else self.epsilon_max self.learn_step_counter += 1 def plot_cost(self): import matplotlib.pyplot as plt1 plt1.figure(2) plt1.plot(np.arange(len(self.cost_his)), self.cost_his) plt1.ylabel('Cost') plt1.xlabel('training steps') plt1.show()