class DDPGAgent:
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, random_seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
random_seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(random_seed)
np.random.seed(random_seed) # set the numpy seed
# Actor Network (w/ Target Network)
self.actor_local = Actor(state_size, action_size,
random_seed).to(device)
self.actor_target = Actor(state_size, action_size,
random_seed).to(device)
self.actor_optimizer = optim.Adam(self.actor_local.parameters(),
lr=LR_ACTOR)
# Critic Network (w/ Target Network)
self.critic_local = Critic(state_size, action_size,
random_seed).to(device)
self.critic_target = Critic(state_size, action_size,
random_seed).to(device)
self.critic_optimizer = optim.Adam(self.critic_local.parameters(),
lr=LR_CRITIC,
weight_decay=WEIGHT_DECAY)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE,
random_seed, device)
# add OU noise for exploration
self.noise = OUNoise(action_size, scale=1.0, sigma=.1)
def reset(self):
self.noise.reset()
def step(self, states, actions, rewards, next_states, dones, time_step):
"""Save experience in replay memory, and use random sample from buffer to learn."""
# Save experience / reward (for each agent)
for state, action, reward, next_state, done in zip(
states, actions, rewards, next_states, dones):
self.memory.add(state, action, reward, next_state, done)
# Learn, if enough samples are available in memory and every 20 steps
if len(self.memory) > BATCH_SIZE and time_step % LEARN_STEPS == 0:
for _ in range(
N_UPDATES): # generate n experiences and realize n updates
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, states, epsilon=0.0, add_noise=True):
"""Returns actions for given state as per current policy."""
states = torch.from_numpy(states).float().to(device)
self.actor_local.eval()
with torch.no_grad():
actions = self.actor_local(states).cpu().data.numpy()
self.actor_local.train()
if add_noise: # add a noise (based on normal distribution) to exploration
actions += self.noise.noise() * epsilon
return np.clip(actions, -1, 1)
def learn(self, experiences, gamma):
"""Update policy and value parameters using given batch of experience tuples.
Q_targets = r + γ * critic_target(next_state, actor_target(next_state))
where:
actor_target(state) -> action
critic_target(state, action) -> Q-value
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
self.__update_critic_local(actions, dones, gamma, next_states, rewards,
states)
self.__update_actor_local(states)
# ----------------------- update target networks ----------------------- #
self.soft_update(self.critic_local, self.critic_target, TAU)
self.soft_update(self.actor_local, self.actor_target, TAU)
def __update_critic_local(self, actions, dones, gamma, next_states,
rewards, states):
# Get predicted next-state actions and Q values from target models
actions_next = self.actor_target(next_states)
Q_targets_next = self.critic_target(next_states, actions_next)
# Compute Q targets for current states (y_i)
Q_targets = rewards + (gamma * Q_targets_next * (1 - dones))
# Compute critic loss
Q_expected = self.critic_local(states, actions)
critic_loss = F.mse_loss(Q_expected, Q_targets)
# Minimize the loss
self.critic_optimizer.zero_grad()
critic_loss.backward()
torch.nn.utils.clip_grad_norm_(self.critic_local.parameters(), 1)
self.critic_optimizer.step()
def __update_actor_local(self, states):
# Compute actor loss
actions_pred = self.actor_local(states)
actor_loss = -self.critic_local(states, actions_pred).mean()
# Minimize the loss
self.actor_optimizer.zero_grad()
actor_loss.backward()
self.actor_optimizer.step()
def soft_update(self, local_model, target_model, tau):
"""Soft update model parameters.
θ_target = τ*θ_local + (1 - τ)*θ_target
Params
======
local_model: PyTorch model (weights will be copied from)
target_model: PyTorch model (weights will be copied to)
tau (float): interpolation parameter
"""
for target_param, local_param in zip(target_model.parameters(),
local_model.parameters()):
target_param.data.copy_(tau * local_param.data +
(1.0 - tau) * target_param.data)
def network_summary(self):
print('- Actor Summary (both local and target): ')
self.actor_local.to(device).summary()
print('- Critic Summary (both local and target): ')
self.actor_local.to(device).summary()
def save(self,
checkpoint_actor_name='checkpoint_actor',
checkpoint_critic_name='checkpoint_critic'):
"""Save the actor and critic network weights"""
torch.save(self.actor_local.state_dict(),
path_result_folder(f'{checkpoint_actor_name}.pth'))
torch.save(self.critic_local.state_dict(),
path_result_folder(f'{checkpoint_critic_name}.pth'))
@staticmethod
def load(env: UnityEnvironment,
random_seed=0,
checkpoint_actor_name='checkpoint_actor',
checkpoint_critic_name='checkpoint_critic'):
"""Load the actor and critic network weights"""
# get the default brain
brain_name = env.brain_names[0]
brain = env.brains[brain_name]
env_info = env.reset(train_mode=True)[brain_name]
state_size = len(env_info.vector_observations[0])
action_size = brain.vector_action_space_size
loaded_agent = DDPGAgent(state_size, action_size, random_seed)
loaded_agent.actor_local.load_state_dict(
torch.load(path_result_folder(f'{checkpoint_actor_name}.pth')))
loaded_agent.critic_local.load_state_dict(
torch.load(path_result_folder(f'{checkpoint_critic_name}.pth')))
return loaded_agent
def main():
env = DialogEnvironment()
experiment_name = args.logdir.split('/')[1] #model name
torch.manual_seed(args.seed)
#TODO
actor = Actor(hidden_size=args.hidden_size,num_layers=args.num_layers,device='cuda',input_size=args.input_size,output_size=args.input_size)
actor.to(device)
actor_optim = optim.Adam(actor.parameters(), lr=args.learning_rate)
# load demonstrations
writer = SummaryWriter(args.logdir)
if args.load_model is not None: #TODO
saved_ckpt_path = os.path.join(os.getcwd(), 'save_model', str(args.load_model))
ckpt = torch.load(saved_ckpt_path)
actor.load_state_dict(ckpt['actor'])
episodes = 0
for iter in range(args.max_iter_num):
actor.eval()
steps = 0
scores = []
states = []
expert_actions = []
while steps < args.batch_size:
scores = []
similarity_scores = []
state, expert_action, raw_state, raw_expert_action = env.reset()
score = 0
similarity_score = 0
state = state[:args.seq_len,:]
expert_action = expert_action[:args.seq_len,:]
state = state.to(device)
expert_action = expert_action.to(device)
states.append(state)
expert_actions.append(expert_action)
similarity_score += get_cosine_sim(expert=expert_action,action=action.squeeze(),seq_len=5)
#print(get_cosine_sim(s1=expert_action,s2=action.squeeze(),seq_len=5),'sim')
if done:
break
episodes += 1
similarity_scores.append(similarity_score)
states = torch.stack(states)
actions_pred , _ = actor(states)
expert_actions = torch.stack(expert_actions)
similarity_score_avg = np.mean(similarity_scores)
print('{}:: {} episode similarity score is {:.2f}'.format(iter, episodes, similarity_score_avg))
actor.train()
loss = F.mse_loss(actions_pred,expert_action)
actor_optim.zero_grad()
actor_optim.step()
# and this is basically all we need to do
train_actor_critic(actor, critic, memory, actor_optim, critic_optim, args)
writer.add_scalar('log/score', float(score_avg), iter)
writer.add_scalar('log/similarity_score', float(similarity_score_avg), iter)
writer.add_text('log/raw_state', raw_state[0],iter)
raw_action = get_raw_action(action) #TODO
writer.add_text('log/raw_action', raw_action,iter)
writer.add_text('log/raw_expert_action', raw_expert_action,iter)
if iter % 100:
score_avg = int(score_avg)
# Open a file with access mode 'a'
file_object = open(experiment_name+'.txt', 'a')
result_str = str(iter) + '|' + raw_state[0] + '|' + raw_action + '|' + raw_expert_action + '\n'
# Append at the end of file
file_object.write(result_str)
# Close the file
file_object.close()
model_path = os.path.join(os.getcwd(),'save_model')
if not os.path.isdir(model_path):
os.makedirs(model_path)
ckpt_path = os.path.join(model_path, experiment_name + '_ckpt_'+ str(score_avg)+'.pth.tar')
save_checkpoint({
'actor': actor.state_dict(),
'critic': critic.state_dict(),
'discrim': discrim.state_dict(),
'args': args,
'score': score_avg,
}, filename=ckpt_path)
def main():
env = DialogEnvironment()
experiment_name = args.logdir.split('/')[1] #model name
torch.manual_seed(args.seed)
#TODO
actor = Actor(hidden_size=args.hidden_size,num_layers=args.num_layers,device='cuda',input_size=args.input_size,output_size=args.input_size)
critic = Critic(hidden_size=args.hidden_size,num_layers=args.num_layers,input_size=args.input_size,seq_len=args.seq_len)
discrim = Discriminator(hidden_size=args.hidden_size,num_layers=args.hidden_size,input_size=args.input_size,seq_len=args.seq_len)
actor.to(device), critic.to(device), discrim.to(device)
actor_optim = optim.Adam(actor.parameters(), lr=args.learning_rate)
critic_optim = optim.Adam(critic.parameters(), lr=args.learning_rate,
weight_decay=args.l2_rate)
discrim_optim = optim.Adam(discrim.parameters(), lr=args.learning_rate)
# load demonstrations
writer = SummaryWriter(args.logdir)
if args.load_model is not None: #TODO
saved_ckpt_path = os.path.join(os.getcwd(), 'save_model', str(args.load_model))
ckpt = torch.load(saved_ckpt_path)
actor.load_state_dict(ckpt['actor'])
critic.load_state_dict(ckpt['critic'])
discrim.load_state_dict(ckpt['discrim'])
episodes = 0
train_discrim_flag = True
for iter in range(args.max_iter_num):
actor.eval(), critic.eval()
memory = deque()
steps = 0
scores = []
similarity_scores = []
while steps < args.total_sample_size:
scores = []
similarity_scores = []
state, expert_action, raw_state, raw_expert_action = env.reset()
score = 0
similarity_score = 0
state = state[:args.seq_len,:]
expert_action = expert_action[:args.seq_len,:]
state = state.to(device)
expert_action = expert_action.to(device)
for _ in range(10000):
steps += 1
mu, std = actor(state.resize(1,args.seq_len,args.input_size)) #TODO: gotta be a better way to resize.
action = get_action(mu.cpu(), std.cpu())[0]
for i in range(5):
emb_sum = expert_action[i,:].sum().cpu().item()
if emb_sum == 0:
# print(i)
action[i:,:] = 0 # manual padding
break
done= env.step(action)
irl_reward = get_reward(discrim, state, action, args)
if done:
mask = 0
else:
mask = 1
memory.append([state, torch.from_numpy(action).to(device), irl_reward, mask,expert_action])
score += irl_reward
similarity_score += get_cosine_sim(expert=expert_action,action=action.squeeze(),seq_len=5)
#print(get_cosine_sim(s1=expert_action,s2=action.squeeze(),seq_len=5),'sim')
if done:
break
episodes += 1
scores.append(score)
similarity_scores.append(similarity_score)
score_avg = np.mean(scores)
similarity_score_avg = np.mean(similarity_scores)
print('{}:: {} episode score is {:.2f}'.format(iter, episodes, score_avg))
print('{}:: {} episode similarity score is {:.2f}'.format(iter, episodes, similarity_score_avg))
actor.train(), critic.train(), discrim.train()
if train_discrim_flag:
expert_acc, learner_acc = train_discrim(discrim, memory, discrim_optim, args)
print("Expert: %.2f%% | Learner: %.2f%%" % (expert_acc * 100, learner_acc * 100))
writer.add_scalar('log/expert_acc', float(expert_acc), iter) #logg
writer.add_scalar('log/learner_acc', float(learner_acc), iter) #logg
writer.add_scalar('log/avg_acc', float(learner_acc + expert_acc)/2, iter) #logg
if args.suspend_accu_exp is not None: #only if not None do we check.
if expert_acc > args.suspend_accu_exp and learner_acc > args.suspend_accu_gen:
train_discrim_flag = False
train_actor_critic(actor, critic, memory, actor_optim, critic_optim, args)
writer.add_scalar('log/score', float(score_avg), iter)
writer.add_scalar('log/similarity_score', float(similarity_score_avg), iter)
writer.add_text('log/raw_state', raw_state[0],iter)
raw_action = get_raw_action(action) #TODO
writer.add_text('log/raw_action', raw_action,iter)
writer.add_text('log/raw_expert_action', raw_expert_action,iter)
if iter % 100:
score_avg = int(score_avg)
# Open a file with access mode 'a'
file_object = open(experiment_name+'.txt', 'a')
result_str = str(iter) + '|' + raw_state[0] + '|' + raw_action + '|' + raw_expert_action + '\n'
# Append at the end of file
file_object.write(result_str)
# Close the file
file_object.close()
model_path = os.path.join(os.getcwd(),'save_model')
if not os.path.isdir(model_path):
os.makedirs(model_path)
ckpt_path = os.path.join(model_path, experiment_name + '_ckpt_'+ str(score_avg)+'.pth.tar')
save_checkpoint({
'actor': actor.state_dict(),
'critic': critic.state_dict(),
'discrim': discrim.state_dict(),
'args': args,
'score': score_avg,
}, filename=ckpt_path)