class DDPG(): """Reinforcement Learning agent that learns using DDPG.""" def __init__(self, task): self.task = task self.state_size = task.state_size self.action_size = task.action_size self.action_low = task.action_low self.action_high = task.action_high # Actor (Policy) Model self.actor_local = Actor(self.state_size, self.action_size, self.action_low, self.action_high) self.actor_target = Actor(self.state_size, self.action_size, self.action_low, self.action_high) # Critic (Value) Model self.critic_local = Critic(self.state_size, self.action_size) self.critic_target = Critic(self.state_size, self.action_size) # Initialize target model parameters with local model parameters self.critic_target.model.set_weights( self.critic_local.model.get_weights()) self.actor_target.model.set_weights( self.actor_local.model.get_weights()) # Noise process self.exploration_mu = 0 #0 self.exploration_theta = 0.15 #0.15 self.exploration_sigma = 0.2 #0.2 self.noise = OUNoise(self.action_size, self.exploration_mu, self.exploration_theta, self.exploration_sigma) # Replay memory self.buffer_size = 100000 #100000 self.batch_size = 64 self.memory = ReplayBuffer(self.buffer_size, self.batch_size) # Algorithm parameters self.gamma = 0.99 # discount factor 0.99 self.tau = 0.01 # for soft update of target parameters 0.01 def reset_episode(self): self.noise.reset() state = self.task.reset() self.last_state = state return state def step(self, action, reward, next_state, done): # Save experience / reward self.memory.add(self.last_state, action, reward, next_state, done) # Learn, if enough samples are available in memory if len(self.memory) > self.batch_size: experiences = self.memory.sample() self.learn(experiences) # Roll over last state and action self.last_state = next_state def act(self, state): """Returns actions for given state(s) as per current policy.""" state = np.reshape(state, [-1, self.state_size]) action = self.actor_local.model.predict(state)[0] # new_thrust = random.gauss(450., 25.) # return [new_thrust + random.gauss(0., 1.) for x in range(4)] return list(action + self.noise.sample()) # add some noise for exploration def learn(self, experiences): """Update policy and value parameters using given batch of experience tuples.""" # Convert experience tuples to separate arrays for each element (states, actions, rewards, etc.) states = np.vstack([e.state for e in experiences if e is not None]) actions = np.array([e.action for e in experiences if e is not None]).astype(np.float32).reshape( -1, self.action_size) rewards = np.array([e.reward for e in experiences if e is not None ]).astype(np.float32).reshape(-1, 1) dones = np.array([e.done for e in experiences if e is not None]).astype(np.uint8).reshape(-1, 1) next_states = np.vstack( [e.next_state for e in experiences if e is not None]) # Get predicted next-state actions and Q values from target models # Q_targets_next = critic_target(next_state, actor_target(next_state)) actions_next = self.actor_target.model.predict_on_batch(next_states) Q_targets_next = self.critic_target.model.predict_on_batch( [next_states, actions_next]) # Compute Q targets for current states and train critic model (local) Q_targets = rewards + self.gamma * Q_targets_next * (1 - dones) self.critic_local.model.train_on_batch(x=[states, actions], y=Q_targets) # Train actor model (local) action_gradients = np.reshape( self.critic_local.get_action_gradients([states, actions, 0]), (-1, self.action_size)) self.actor_local.train_fn([states, action_gradients, 1]) # custom training function # Soft-update target models self.soft_update(self.critic_local.model, self.critic_target.model) self.soft_update(self.actor_local.model, self.actor_target.model) def soft_update(self, local_model, target_model): """Soft update model parameters.""" local_weights = np.array(local_model.get_weights()) target_weights = np.array(target_model.get_weights()) assert len(local_weights) == len( target_weights ), "Local and target model parameters must have the same size" new_weights = self.tau * local_weights + (1 - self.tau) * target_weights target_model.set_weights(new_weights)
class DDPG(): """Reinforcement Learning agent that learns using DDPG.""" def __init__(self, task): self.task = task self.state_size = task.state_size self.action_size = task.action_size self.action_low = task.action_low self.action_high = task.action_high # Actor (Policy) Model self.actor_local = Actor(self.state_size, self.action_size, self.action_low, self.action_high) self.actor_target = Actor(self.state_size, self.action_size, self.action_low, self.action_high) # Critic (Value) Model self.critic_local = Critic(self.state_size, self.action_size) self.critic_target = Critic(self.state_size, self.action_size) # Initialize target model parameters with local model parameters self.critic_target.model.set_weights(self.critic_local.model.get_weights()) self.actor_target.model.set_weights(self.actor_local.model.get_weights()) # Noise process self.exploration_mu = 0 #0 self.exploration_theta = 0.15 self.exploration_sigma = 0.2 self.noise = OUNoise(self.action_size, self.exploration_mu, self.exploration_theta, self.exploration_sigma) # Replay memory self.buffer_size = 100000 self.batch_size = 64 self.memory = ReplayBuffer(self.buffer_size, self.batch_size) # Algorithm parameters self.gamma = 0.99 # discount factor - 0.99 self.tau = 0.01 # for soft update of target parameters - 0.01 # Score tracker and learning parameters self.best_w = None self.best_score = -np.inf self.score = -np.inf def reset_episode(self): self.total_reward = 0.0 self.count = 0 self.noise.reset() state = self.task.reset() self.last_state = state return state def step(self, action, reward, next_state, done): # Save experience / reward self.total_reward += reward self.count += 1 self.memory.add(self.last_state, action, reward, next_state, done) # Learn, if enough samples are available in memory if len(self.memory) > self.batch_size: experiences = self.memory.sample() self.learn(experiences) # Roll over last state and action self.last_state = next_state def act(self, state): """Returns actions for given state(s) as per current policy.""" state = np.reshape(state, [-1, self.state_size]) action = self.actor_local.model.predict(state)[0] return list(action + self.noise.sample()) # add some noise for exploration def learn(self, experiences): """Update policy and value parameters using given batch of experience tuples.""" self.score = self.total_reward / float(self.count) if self.count else 0.0 if self.score > self.best_score: self.best_score = self.score # Convert experience tuples to separate arrays for each element (states, actions, rewards, etc.) states = np.vstack([e.state for e in experiences if e is not None]) actions = np.array([e.action for e in experiences if e is not None]).astype(np.float32).reshape(-1, self.action_size) rewards = np.array([e.reward for e in experiences if e is not None]).astype(np.float32).reshape(-1, 1) dones = np.array([e.done for e in experiences if e is not None]).astype(np.uint8).reshape(-1, 1) next_states = np.vstack([e.next_state for e in experiences if e is not None]) # Get predicted next-state actions and Q values from target models # Q_targets_next = critic_target(next_state, actor_target(next_state)) actions_next = self.actor_target.model.predict_on_batch(next_states) Q_targets_next = self.critic_target.model.predict_on_batch([next_states, actions_next]) # Compute Q targets for current states and train critic model (local) Q_targets = rewards + self.gamma * Q_targets_next * (1 - dones) self.critic_local.model.train_on_batch(x=[states, actions], y=Q_targets) # Train actor model (local) action_gradients = np.reshape(self.critic_local.get_action_gradients([states, actions, 0]), (-1, self.action_size)) self.actor_local.train_fn([states, action_gradients, 1]) # custom training function # Soft-update target models self.soft_update(self.critic_local.model, self.critic_target.model) self.soft_update(self.actor_local.model, self.actor_target.model) def soft_update(self, local_model, target_model): """Soft update model parameters.""" local_weights = np.array(local_model.get_weights()) target_weights = np.array(target_model.get_weights()) assert len(local_weights) == len(target_weights), "Local and target model parameters must have the same size" new_weights = self.tau * local_weights + (1 - self.tau) * target_weights target_model.set_weights(new_weights)
class DDPG(): """Reinforcement Learning agent that learns using DDPG.""" def __init__(self, task): self.name = "DDPG" self.task = task self.state_size = task.state_size self.action_size = task.action_size self.action_low = task.action_low self.action_high = task.action_high # Actor (Policy) Model self.actor_local = Actor(self.state_size, self.action_size, self.action_low, self.action_high, 'actor_local') self.actor_target = Actor(self.state_size, self.action_size, self.action_low, self.action_high, 'actor_target') # Critic (Value) Model self.critic_local = Critic(self.state_size, self.action_size, 'critic_local') self.critic_target = Critic(self.state_size, self.action_size, 'critic_target') # Initialize target model parameters with local model parameters self.critic_target.model.set_weights( self.critic_local.model.get_weights()) self.actor_target.model.set_weights( self.actor_local.model.get_weights()) # Noise process self.exploration_mu = 0.0 self.exploration_theta = 0.15 self.exploration_sigma = 0.2 self.noise = OUNoise(self.action_size, self.exploration_mu, self.exploration_theta, self.exploration_sigma) # Replay memory self.buffer_size = 100000 self.batch_size = 64 self.memory = ReplayBuffer(self.buffer_size, self.batch_size) # Algorithm parameters self.gamma = 0.99 # discount factor self.tau = 0.001 # for soft update of target parameters # Reward counter self.total_reward = 0 self.n_steps = 0 def load(self): self.actor_local.load() self.actor_target.load() self.critic_local.load() self.critic_target.load() print("Agent's weights loaded from disk.") def save(self): self.actor_local.save() self.actor_target.save() self.critic_local.save() self.critic_target.save() print("Agent's weights saved to disk.") def reset_episode(self): self.total_reward = 0 self.n_steps = 0 self.noise.reset() state = self.task.reset() self.last_state = state return state def step(self, action, reward, next_state, done): # Save experience / reward self.memory.add(self.last_state, action, reward, next_state, done) # Add reward to total self.total_reward += reward self.n_steps += 1 # Learn, if enough samples are available in memory if len(self.memory) > self.batch_size: experiences = self.memory.sample() self.learn(experiences) # Roll over last state and action self.last_state = next_state def act(self, state, add_noise=True): """Returns actions for given state(s) as per current policy.""" state = np.reshape(state, [-1, self.state_size]) action = self.actor_local.model.predict(state)[0] # Hack, rescale rotor revs to +-5 range from average # rev_mean = np.mean(action) # action = (action-450)/450 # action *= 50 # action += rev_mean if add_noise: action += self.noise.sample() # additive noise for exploration return list(action) def learn(self, experiences): """Update policy and value parameters using given batch of experience tuples.""" # Convert experience tuples to separate arrays for each element (states, actions, rewards, etc.) states = np.vstack([e.state for e in experiences if e is not None]) actions = np.array([e.action for e in experiences if e is not None]).astype(np.float32).reshape( -1, self.action_size) rewards = np.array([e.reward for e in experiences if e is not None ]).astype(np.float32).reshape(-1, 1) dones = np.array([e.done for e in experiences if e is not None]).astype(np.uint8).reshape(-1, 1) next_states = np.vstack( [e.next_state for e in experiences if e is not None]) # Get predicted next-state actions and Q values from target models # Q_targets_next = critic_target(next_state, actor_target(next_state)) actions_next = self.actor_target.model.predict_on_batch(next_states) Q_targets_next = self.critic_target.model.predict_on_batch( [next_states, actions_next]) # Compute Q targets for current states and train critic model (local) Q_targets = rewards + self.gamma * Q_targets_next * (1 - dones) self.critic_local.model.train_on_batch(x=[states, actions], y=Q_targets) # Train actor model (local) action_gradients = np.reshape( self.critic_local.get_action_gradients([states, actions, 0]), (-1, self.action_size)) self.actor_local.train_fn([states, action_gradients, 1]) # custom training function # Soft-update target models self.soft_update(self.critic_local.model, self.critic_target.model) self.soft_update(self.actor_local.model, self.actor_target.model) def soft_update(self, local_model, target_model): """Soft update model parameters.""" local_weights = np.array(local_model.get_weights()) target_weights = np.array(target_model.get_weights()) assert len(local_weights) == len( target_weights ), "Local and target model parameters must have the same size" new_weights = self.tau * local_weights + (1 - self.tau) * target_weights target_model.set_weights(new_weights)
class DDPG(): """Reinforcement Learning agent that learns using DDPG.""" def __init__(self, task): # Print debug statements self.debug = False # Task (environment) information self.task = task self.state_size = task.state_size self.action_size = task.action_size self.action_low = task.action_low self.action_high = task.action_high self.action_range = self.action_high - self.action_low # Actor (policy) model self.actor_lr = 1e-4 self.actor_local = Actor(self.state_size, self.action_size, self.action_low, self.action_high, learning_rate=self.actor_lr) self.actor_target = Actor(self.state_size, self.action_size, self.action_low, self.action_high, learning_rate=self.actor_lr) # Critic (value) model self.critic_lr = 1e-4 self.critic_local = Critic(self.state_size, self.action_size, learning_rate=self.critic_lr) self.critic_target = Critic(self.state_size, self.action_size, learning_rate=self.critic_lr) # Print Actor / Critic NN architectures if self.debug: self.actor_local.model.summary() self.critic_local.model.summary() # Initialize target model parameters with local model parameters self.critic_target.model.set_weights( self.critic_local.model.get_weights()) self.actor_target.model.set_weights( self.actor_local.model.get_weights()) # Noise process self.exploration_mu = 0 self.exploration_theta = 1.5e-1 self.exploration_sigma = 2.0e-2 self.noise = OUNoise(self.action_size, mu=self.exploration_mu, theta=self.exploration_theta, sigma=self.exploration_sigma) # Replay memory self.buffer_size = 100000 self.batch_size = 128 self.memory = ReplayBuffer(self.buffer_size, self.batch_size) # Algorithm parameters self.gamma = 0.99 # discount factor self.tau = 0.001 # for soft update of target parameters # Score tracker self.best_score = -np.inf self.total_reward = 0.0 self.count = 0 # Episode variables self.reset_episode() def reset_episode(self): score = self.total_reward / float( self.count) if self.count else -np.inf if score > self.best_score: self.best_score = score self.total_reward = 0.0 self.count = 0 self.noise.reset() state = self.task.reset() self.last_state = state return state def soft_update(self, local_model, target_model): """Soft update model parameters.""" local_weights = np.array(local_model.get_weights()) target_weights = np.array(target_model.get_weights()) assert len(local_weights) == len( target_weights ), "Local and target model parameters must have the same size" new_weights = self.tau * local_weights + (1 - self.tau) * target_weights target_model.set_weights(new_weights) def step(self, action, reward, next_state, done): # Save experience / reward self.memory.add(self.last_state, action, reward, next_state, done) self.total_reward += reward self.count += 1 # Learn if enough samples are in memory if len(self.memory) > self.batch_size: experiences = self.memory.sample() self.learn(experiences) # Roll over last state and action self.last_state = next_state def act(self, state): """Returns actions for given state(s) as per current policy.""" state = np.reshape(state, [-1, self.state_size]) action = self.actor_local.model.predict(state)[0] return list(action + self.noise.sample()) # Add some noise for exploration def learn(self, experiences): """Update policy and value parameters using given batch of experience tuples.""" states = np.vstack([e.state for e in experiences if e is not None]) actions = np.array([e.action for e in experiences if e is not None]).astype(np.float32).reshape( -1, self.action_size) rewards = np.array([e.reward for e in experiences if e is not None ]).astype(np.float32).reshape(-1, 1) dones = np.array([e.done for e in experiences if e is not None]).astype(np.uint8).reshape(-1, 1) next_states = np.vstack( [e.next_state for e in experiences if e is not None]) # Get predicted next state actions and Q values from target networks actions_next = self.actor_target.model.predict_on_batch(next_states) Q_targets_next = self.critic_target.model.predict_on_batch( [next_states, actions_next]) # Compute Q targets for current states and train critic model (local) Q_targets = rewards + self.gamma * Q_targets_next * (1 - dones) self.critic_local.model.train_on_batch(x=[states, actions], y=Q_targets) # Train actor model (local) action_gradients = np.reshape( self.critic_local.get_action_gradients([states, actions, 0]), (-1, self.action_size)) self.actor_local.train_fn([states, action_gradients, 1]) # custom training function # Soft update target models self.soft_update(self.critic_local.model, self.critic_target.model) self.soft_update(self.actor_local.model, self.actor_target.model)