class ddqn_Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
self.wQ =0
self.wQ1=0
self.wQ2=0
# Q-Network
self.qnetwork_Qa = QNetwork(state_size, action_size, seed).to(device)
self.qnetwork_Qb = QNetwork(state_size, action_size, seed).to(device)
self.optimizer_Qa = optim.Adam(self.qnetwork_Qa.parameters(), lr=LR)
self.optimizer_Qb = optim.Adam(self.qnetwork_Qb.parameters(), lr=LR)
# Replay memory
self.memory = ddqn_ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def print_result():
somme=self.wQ1+self.wQ2+0.0000001
print("qQ1=",self.wQ1/somme," qQ2=",self.wQ2/somme)
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act_a(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_Qa.eval()
with torch.no_grad():
action_values = self.qnetwork_Qa(state)
self.qnetwork_Qa.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def act_b(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_Qb.eval()
with torch.no_grad():
action_values = self.qnetwork_Qb(state)
self.qnetwork_Qb.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def act(self,state,eps=0.):
self.wQ=np.random.choice([0, 1])
if(self.wQ):
return self.act_a(state, eps)
else:
return self.act_b(state, eps)
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
#
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
"*** YOUR CODE HERE ***"
if self.wQ:
# wQ take either 0 or 1 based on uniform random function.
yj=self.qnetwork_Qb.forward(next_states).detach().max(1)[0].unsqueeze(1)
Q_targets=rewards+gamma*yj*(1.0-dones)
# Get expected Q values from local model
Q_expected = self.qnetwork_Qa.forward(states).gather(1, actions)
# Compute loss: Mean Square Error by element
loss = F.mse_loss(Q_expected, Q_targets)
# Minimize the loss
self.optimizer_Qa.zero_grad()
loss.backward()
self.optimizer_Qa.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_Qa, self.qnetwork_Qb, TAU)
else:
yj=self.qnetwork_Qa.forward(next_states).detach().max(1)[0].unsqueeze(1)
Q_targets=rewards+gamma*yj*(1.0-dones)
# Get expected Q values from local model
Q_expected = self.qnetwork_Qb.forward(states).gather(1, actions)
# Compute loss: Mean Square Error by element
loss = F.mse_loss(Q_expected, Q_targets)
# Minimize the loss
self.optimizer_Qb.zero_grad()
loss.backward()
self.optimizer_Qb.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_Qb, self.qnetwork_Qa, TAU)
def soft_update(self, local_model, target_model, tau):
"""Soft update model parameters.
teta_target = ro*teta_local + (1 - ro)*teta_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)
class Agent():
def __init__(self, state_size, action_size, seed):
"""
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.q_network_local = QNetwork(state_size, action_size, seed).to(device)
self.q_network_target = QNetwork(state_size, action_size, seed).to(device)
self.optimizer = optim.Adam(self.q_network_local.parameters(), lr=LR)
# Replay buffer
self.memory = ReplayBuffer(BATCH_SIZE, action_size, BUFFER_SIZE, seed)
# Ini
self.t_step = 0
def soft_update(self, local_network, target_network, tau):
"""Soft update model parameters
"""
for target_param, local_param in zip(target_network.parameters(), local_network.parameters()):
target_param.data.copy_(tau*local_param.data + (1-tau)*target_param.data)
def learn(self, experiences, gamma):
"""
"""
states, actions, rewards, next_states, dones = experiences
Q_expected = self.q_network_local.forward(states).gather(1, actions)
Q_targets_next = self.q_network_target.forward(next_states).detach().max(1)[0].unsqueeze(1)
Q_targets = rewards + gamma*Q_targets_next*(1-dones)
self.optimizer.zero_grad()
loss = F.mse_loss(Q_expected, Q_targets)
loss.backward()
self.optimizer.step()
# Update the target network
self.soft_update(self.q_network_local, self.q_network_target, TAU)
def act(self, state, epsilon=0.):
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.q_network_local.eval()
with torch.no_grad():
action_values = self.q_network_local(state)
self.q_network_local.train()
do_exploration = (random.random()<epsilon)
if do_exploration:
action = np.random.randint(self.action_size)
else:
action = np.argmax(action_values.cpu().data.numpy())
return action
def step(self, state, action, reward, next_state, done):
# save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# update self.t_step
self.t_step = (self.t_step+1) % UPDATE_EVERY
# learn from this batch
if self.t_step == 0:
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
class DQN():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, config):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.config = config
self.state_size = state_size
self.action_size = action_size
nodes = self.config.get("nodes", [128, 64])
self.seed = self.config.get("seed", 0)
lr = self.config.get("lr", 1e-4)
memory_size = self.config.get("memory_size", 100000)
self.batch_size = self.config.get("batch_size", 256)
self.discount = self.config.get("discount", 0.9)
self.tau = self.config.get("tau", 0.001)
self.epsilon = self.config.get("epsilon", 0.1)
self.epsilon_end = self.config.get("epsilon_end", 0.0001)
self.epsilon_decay = self.config.get("epsilon_decay", 0.995)
self.learn_every = self.config.get("learn_every", 4)
self.dqn = self.config.get("dqn", "simple")
self.per = self.config.get("per", False)
np.random.seed(self.seed)
random.seed(self.seed)
torch.manual_seed(self.seed)
# Q-Network
if self.dqn == "dueling":
self.qnetwork_local = Dueling_QNetwork(state_size, action_size,
self.seed).to(device)
self.qnetwork_target = Dueling_QNetwork(state_size, action_size,
self.seed).to(device)
else:
self.qnetwork_local = QNetwork(state_size,
action_size,
self.seed,
nodes=nodes).to(device)
self.qnetwork_target = QNetwork(state_size,
action_size,
self.seed,
nodes=nodes).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=lr)
#self.optimizer = optim.RMSprop(self.qnetwork_local.parameters(), lr= lr)
# Replay memory
if self.per:
self.memory = Memory(memory_size)
else:
self.memory = ReplayBuffer(memory_size, self.batch_size, self.seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
self.scores = []
def add_sample(self, state, action, reward, next_state, done):
if self.per == False:
self.memory.add((state, action, reward, next_state, 1 * done))
else:
target = self.qnetwork_local(
Variable(torch.FloatTensor(state)).to(device)).data
old_val = target[action]
target_val = self.qnetwork_target(
Variable(torch.FloatTensor(next_state)).to(device)).data
if done:
target[action] = reward
else:
target[action] = reward + self.discount * torch.max(target_val)
error = abs(old_val - target[action])
self.memory.add(error,
(state, action, reward, next_state, 1 * done))
def act(self, state, add_noise=True):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval() #set to eval mode
with torch.no_grad():
action_values = self.qnetwork_local.forward(state)
self.qnetwork_local.train() # set to training mode
# Epsilon-greedy action selection
if add_noise == False: eps = 0.0
else: eps = self.epsilon
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.add_sample(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % self.learn_every
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > self.batch_size:
self.learn()
def learn(self):
if self.per:
mini_batch, idxs, is_weights = self.memory.sample(self.batch_size)
mini_batch = np.array(mini_batch).transpose()
states = torch.from_numpy(np.vstack(
mini_batch[0])).float().to(device)
actions = torch.from_numpy(np.vstack(
mini_batch[1])).long().to(device)
rewards = torch.from_numpy(np.vstack(
mini_batch[2])).float().to(device)
next_states = torch.from_numpy(np.vstack(
mini_batch[3])).float().to(device)
dones = torch.from_numpy(
np.vstack(mini_batch[4]).astype(np.uint8)).float().to(device)
else:
states, actions, rewards, next_states, dones = self.memory.sample()
# Get expected Q values from local model
Q_expected = self.qnetwork_local(states).gather(1, actions.long())
if self.dqn == "simple":
# Get max predicted Q values (for next states) from target model
Q_targets_next = self.qnetwork_target(next_states).detach().max(
1)[0].unsqueeze(1)
elif self.dqn == "double": # Double DQN
_, Q_targets_next = self.qnetwork_local(next_states).detach().max(
1) # Get argmax
Q_targets_next = self.qnetwork_target(next_states).detach().gather(
1, Q_targets_next.unsqueeze(1))
elif self.dqn == "dueling": # Dueling
_, Q_targets_next = self.qnetwork_local(next_states).detach().max(
1) # Get argmax
Q_targets_next = self.qnetwork_target(next_states).detach().gather(
1, Q_targets_next.unsqueeze(1))
else:
raise OSError(
'Error in DQN: {}. Options: simple, double, dueling.'.format(
self.dqn))
# Compute Q targets for current states
Q_targets = rewards + (self.discount * Q_targets_next * (1 - dones))
"""
# update priority
if self.per:
error= abs(Q_expected - Q_targets)
errors = error.data.cpu().numpy()
for i in range(len(idxs)):
idx = idxs[i]
self.memory.update(idx, errors[i])
"""
# Compute loss
loss = F.mse_loss(Q_expected, Q_targets)
#loss = F.smooth_l1_loss(Q_expected, Q_targets)
# Minimize the loss
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# ------------------- update target network -------------------
self.soft_update(self.qnetwork_local, self.qnetwork_target)
def soft_update(self, local_model, target_model):
for target_param, local_param in zip(target_model.parameters(),
local_model.parameters()):
target_param.data.copy_(self.tau * local_param.data +
(1.0 - self.tau) * target_param.data)
def reset(self):
pass
def update(self, score):
self.scores.append(score)
self.epsilon = max(self.epsilon_end, self.epsilon_decay *
self.epsilon) # decrease epsilon
def save(self, filename):
torch.save(self.qnetwork_local.state_dict(), filename)
def load(self, filename):
self.qnetwork_local.load_state_dict(torch.load(filename))
class PrioritizedAgent:
'''Interact with and learn from the environment.
The agent uses prioritized experience replay.
'''
def __init__(self, state_size, action_size, seed, is_double_q=False):
'''Initialize an Agent.
Params
======
state_size (int): the dimension of the state
action_size (int): the number of actions
seed (int): random seed
'''
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
self.t_step = 0 # Initialize time step (for tracking LEARN_EVERY_STEP and UPDATE_EVERY_STEP)
self.running_loss = 0
self.training_cnt = 0
self.is_double_q = is_double_q
self.qnetwork_local = QNetwork(self.state_size, self.action_size,
seed).to(device)
self.qnetowrk_target = QNetwork(self.state_size, self.action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
self.prioritized_memory = PrioritizedMemory(BATCH_SIZE, BUFFER_SIZE,
seed)
def act(self, state, mode, epsilon=None):
'''Returns actions for given state as per current policy.
Params
======
state (array): current state
mode (string): train or test
epsilon (float): for epsilon-greedy action selection
'''
state = torch.from_numpy(state).float().unsqueeze(0).to(
device) # shape of state (1, state)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local.forward(state)
self.qnetwork_local.train()
if mode == 'test':
action = np.argmax(action_values.cpu().data.numpy()
) # pull action values from gpu to local cpu
elif mode == 'train':
if random.random() <= epsilon: # random action
action = random.choice(np.arange(self.action_size))
else: # greedy action
action = np.argmax(action_values.cpu().data.numpy(
)) # pull action values from gpu to local cpu
return action
def step(self, state, action, reward, next_state, done):
# add new experience in memory
self.prioritized_memory.add(state, action, reward, next_state, done)
# activate learning every few steps
self.t_step = self.t_step + 1
if self.t_step % LEARN_EVERY_STEP == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.prioritized_memory) >= BUFFER_SIZE:
idxes, experiences, is_weights = self.prioritized_memory.sample(
device)
self.learn(experiences,
GAMMA,
is_weights=is_weights,
leaf_idxes=idxes)
def learn(self, experiences, gamma, is_weights, leaf_idxes):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
is_weights (tensor array): importance-sampling weights for prioritized experience replay
leaf_idxes (numpy array): indexes for update priorities in SumTree
"""
states, actions, rewards, next_states, dones = experiences
q_local_chosen_action_values = self.qnetwork_local.forward(
states).gather(1, actions)
q_target_action_values = self.qnetowrk_target.forward(
next_states).detach()
if self.is_double_q == True:
q_local_next_actions = self.qnetwork_local.forward(
next_states).detach().max(1)[1].unsqueeze(
1) # shape (batch_size, 1)
q_target_best_action_values = q_target_action_values.gather(
1, q_local_next_actions) # Double DQN
elif self.is_double_q == False:
q_target_best_action_values = q_target_action_values.max(
1)[0].unsqueeze(1) # shape (batch_size, 1)
rewards = rewards.tanh(
) # rewards are clipped to be in [-1,1], referencing from original paper
q_target_values = rewards + gamma * q_target_best_action_values * (
1 - dones) # zero value for terminal state
td_errors = (q_target_values - q_local_chosen_action_values).tanh(
) # TD-errors are clipped to be in [-1,1], referencing from original paper
abs_errors = td_errors.abs().cpu().data.numpy() # pull back to cpu
self.prioritized_memory.batch_update(
leaf_idxes, abs_errors) # update priorities in SumTree
loss = (is_weights * (td_errors**2)).mean(
) # adjust squared TD loss by Importance-Sampling Weights
self.running_loss += float(loss.cpu().data.numpy())
self.training_cnt += 1
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
if self.t_step % UPDATE_EVERY_STEP == 0:
self.update(self.qnetwork_local, self.qnetowrk_target)
def update(self, local_netowrk, target_network):
"""Hard update model parameters, as indicated in original paper.
Params
======
local_model (PyTorch model): weights will be copied from
target_model (PyTorch model): weights will be copied to
"""
for local_param, target_param in zip(local_netowrk.parameters(),
target_network.parameters()):
target_param.data.copy_(local_param.data)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy()) #expliding
else:
return random.choice(np.arange(self.action_size)) #exploration
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
"*** YOUR CODE HERE ***"
"""
for i in range(BATCH_SIZE):
if not dones[i]:
max_val = self.qnetwork_target(next_states[i])
best_val = max_val.argmax()
target = rewards[i] + gamma*(max_val[best_val])
else:
target = rewards[i]
current = self.qnetwork_local(states[i])[actions[i]]
#current = self.qnetwork_local(states).gather(-1, actions.reshape(actions.size()[0], 1))
self.loss = F.mse_loss(target, current)
#self.loss.requires_grad = True
self.optimizer.zero_grad()
self.loss.backward()
self.optimizer.step()
"""
current = self.qnetwork_local(states).gather(
-1, actions.reshape(actions.size()[0], 1))
target1 = self.qnetwork_local.forward(next_states)
max_val = target1.argmax(dim=-1)
final = target1.gather(-1, max_val.reshape(max_val.shape[0], 1))
target2 = self.qnetwork_target.forward(next_states)
max_val = target2.argmax(dim=-1)
final2 = target2.gather(-1, max_val.reshape(max_val.shape[0], 1))
data = torch.cat([final, final2], 1)
min_val = data.argmin(dim=-1)
final = data.gather(-1, min_val.reshape(min_val.shape[0], 1))
target = rewards + gamma * final * (1 - dones)
self.loss = F.mse_loss(current, target)
self.optimizer.zero_grad()
self.loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
"*** YOUR CODE HERE ***"
self.qnetwork_local.train()
#state_action_values = self.qnetwork_local.forward(states)
#computing max predicted Q values (for next states) from target model
Q_targets_next = self.qnetwork_target.forward(
next_states).detach().max(1)[0].unsqueeze(1)
#compute targets for current states
Q_targets = rewards + (gamma * Q_targets_next * (1 - dones))
#computing best Q-action value (for each state) from local model
Q_expected = self.qnetwork_local.forward(states).gather(1, actions)
#loss = self.criterion(state_action_values, expected_state_action_values)
loss = F.mse_loss(Q_expected, Q_targets)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
def __init__(self, state_size, action_size, seed):
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
for target_param, param in zip(self.qnetwork_local.parameters(),
self.qnetwork_target.parameters()):
target_param.data.copy_(param)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
states, actions, rewards, next_states, dones = experiences
actions = actions.view(actions.size(0), 1)
dones = dones.view(dones.size(0), 1)
curr_Q = self.qnetwork_local.forward(states).gather(1, actions)
next_Q = self.qnetwork_target.forward(next_states)
max_next_Q = torch.max(next_Q, 1)[0]
max_next_Q = max_next_Q.view(max_next_Q.size(0), 1)
expected_Q = rewards + (1 - dones) * gamma * max_next_Q
loss = F.mse_loss(curr_Q, expected_Q.detach())
# Q_targets_next = self.qnetwork_target(next_states).detach().max(1)[0].unsqueeze(1)
# Q_targets = rewards + (gamma * Q_targets_next * (1-dones))
# Q_expected = self.qnetwork_local(states).gather(1, actions)
# loss = F.mse_loss(Q_expected, Q_targets)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
for target_param, param in zip(self.qnetwork_target.parameters(),
self.qnetwork_local.parameters()):
target_param.data.copy_(TAU * param + (1 - TAU) * target_param)
def soft_update(self, local_model, target_model, tau):
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)
class Agent():
def __init__(self, state_size, action_size, seed):
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size, seed)
self.qnetwork_target = QNetwork(state_size, action_size, seed)
self.qnetwork_local.load_model("./dqn_LL_model data.pickle")
self.qnetwork_target.load_model("./dqn_LL_model data.pickle")
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
self.loss = 0
self.loss_list = []
def step(self, state, action, reward, next_state, done, t_step):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = t_step
if self.t_step % UPDATE_EVERY == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > 100 * BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
"""
action_values = self.qnetwork_local.forward(state)
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values)
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
"""
states, actions, rewards, next_states, dones = experiences
for time in range(BATCH_SIZE):
# compute Q_target from the target network inputing next_state
Q_target_av = np.max(
self.qnetwork_target.forward(next_states[time]))
Q_target = rewards[time] + gamma * (Q_target_av) * (
1 - dones[time]) # if done, than the second will not be added
# compute the Q_expected
Q_expected = self.qnetwork_local.forward(
states[time]
) # get q value for corrosponding action along dimension 1 of 64,4 matrix
self.qnetwork_local.backward(Q_target, "MSE", actions[time])
self.loss_list.append((Q_target - Q_expected[actions[time]])**2)
self.loss = np.mean(self.loss_list)
self.qnetwork_local.step()
self.loss_list.clear()
# update target network #
if self.t_step % UPDATE_FREQUENCY == 0:
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
def soft_update(self, local_model, target_model, tau):
"""Soft update model parameters.
θ_target = tau*θ_local + (1 - tau)*θ_target
"""
self.qnetwork_target.soft_update(local_model, TAU)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Parameters:
==========
state_size (int): This is the dimension of each state.
action_size (int): This is the dimension of each action.
seed (int): This is the random seed.
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network (local and target one)
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
# mounting an Adam optimizer for the backward propagation
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# mounting an MSE Loss function
self.criterion = nn.MSELoss()
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps).
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory.
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn.
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Parameters:
==========
state (array_like): The current state.
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
self.optimizer.zero_grad()
# Forward and backward passes
output = self.qnetwork_local.forward(states).gather(1, actions)
loss = self.criterion(output,
self.targets(gamma, rewards, next_states, dones))
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
def targets(self, gamma, rewards, next_states, dones):
with torch.no_grad():
q = self.qnetwork_target.forward(next_states)
y = torch.add(rewards,
torch.mul(torch.max(q, dim=1, keepdim=True)[0],
gamma)) * (1 - dones)
return y
def soft_update(self, local_model, target_model, tau):
"""Soft update model parameters.
θ_target = τ*θ_local + (1 - τ)*θ_target
Parameters:
==========
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)
class PrioritizedAgent:
'''Interact with and learn from the environment.'''
def __init__(self, state_size, action_size, seed, is_prioritized_sample=False):
'''Initialize an Agent.
Params
======
state_size (int): the dimension of the state
action_size (int): the number of actions
seed (int): random seed
'''
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
self.t_step = 0 # Initialize time step (for tracking LEARN_EVERY_STEP and UPDATE_EVERY_STEP)
self.is_prioritized_sample = is_prioritized_sample
self.qnetwork_local = QNetwork(self.state_size, self.action_size, seed).to(device)
self.qnetowrk_target = QNetwork(self.state_size, self.action_size, seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
if self.is_prioritized_sample == False:
self.replay_memory = ReplayMemory(BATCH_SIZE, BUFFER_SIZE, seed)
else:
self.replay_memory = PrioritizedReplayMemory(BATCH_SIZE, BUFFER_SIZE, seed)
def act(self, state, epsilon=0.):
'''Returns actions for given state as per current policy.
Params
======
state (array-like): current state
epsilon (float): for epsilon-greedy action selection
'''
state = torch.from_numpy(state).float().unsqueeze(0).to(device) # shape of state (1, state)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local.forward(state)
self.qnetwork_local.train()
if random.random() <= epsilon: # random action
action = random.choice(np.arange(self.action_size))
else: # greedy action
action = np.argmax(action_values.cpu().data.numpy()) # pull action values from gpu to local cpu
return action
def step(self, state, action, reward, next_state, done):
# add new experience in memory
self.replay_memory.add(state, action, reward, next_state, done)
# activate learning every few steps
self.t_step = self.t_step + 1
if self.t_step % LEARN_EVERY_STEP == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.replay_memory) >= BUFFER_SIZE and self.is_prioritized_sample==False:
experiences = self.replay_memory.sample(device)
self.learn(experiences, GAMMA)
elif len(self.replay_memory) >= BUFFER_SIZE and self.is_prioritized_sample==True:
batch_idx, experiences, batch_ISWeights = self.replay_memory.sample(device)
self.learn(experiences, GAMMA, ISWeights=batch_ISWeights, leaf_idxes=batch_idx)
def learn(self, experiences, gamma, ISWeights=None, leaf_idxes=None):
"""Update value parameters using given batch of experience tuples.
If is_prioritized_sample, then weights update is adjusted by ISWeights.
In addition, Double DQN is optional.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
ISWeights (tensor array): importance-sampling weights for prioritized experience replay
leaf_idxes (numpy array): indexes for update priorities in SumTree
"""
# compute and minimize the loss
if self.is_prioritized_sample == False:
states, actions, rewards, next_states, dones = experiences
q_local_chosen_action_values = self.qnetwork_local.forward(states).gather(1, actions)
q_target_action_values = self.qnetowrk_target.forward(next_states).detach() # # detach from graph, don't backpropagate
q_target_best_action_values = q_target_action_values.max(1)[0].unsqueeze(1) # shape (batch_size, 1)
q_target_values = rewards + gamma * q_target_best_action_values * (1 - dones) # zero value for terminal state
loss = F.mse_loss(q_local_chosen_action_values, q_target_values)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
else:
states, actions, rewards, next_states, dones = experiences
q_local_chosen_action_values = self.qnetwork_local.forward(states).gather(1, actions)
#q_local_next_actions = self.qnetwork_local.forward(next_states).detach().max(1)[1].unsqueeze(1) # shape (batch_size, 1)
q_target_action_values = self.qnetowrk_target.forward(next_states).detach()
q_target_best_action_values = q_target_action_values.max(1)[0].unsqueeze(1) # shape (batch_size, 1)
#q_target_best_action_values = q_target_action_values.gather(1, q_local_next_actions) # Double DQN
q_target_values = rewards + gamma * q_target_best_action_values * (1 - dones) # zero value for terminal state
abs_errors = torch.abs(q_target_values - q_local_chosen_action_values).cpu().data.numpy() # pull back to cpu
self.replay_memory.batch_update(leaf_idxes, abs_errors) # update priorities in SumTree
loss = F.mse_loss(q_local_chosen_action_values, q_target_best_action_values, reduce=False)
loss = (ISWeights * loss).mean() # adjust TD loss by Importance-Sampling Weights
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
if self.t_step % UPDATE_EVERY_STEP == 0:
self.update(self.qnetwork_local, self.qnetowrk_target)
def update(self, local_netowrk, target_network):
"""Hard update model parameters, as indicated in original paper.
Params
======
local_model (PyTorch model): weights will be copied from
target_model (PyTorch model): weights will be copied to
"""
for local_param, target_param in zip(local_netowrk.parameters(), target_network.parameters()):
target_param.data.copy_(local_param.data)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
if torch.cuda.device_count() > 1:
print("Let's use", torch.cuda.device_count(), "GPUs!")
# dim = 0 [30, xxx] -> [10, ...], [10, ...], [10, ...] on 3 GPUs
net = nn.DataParallel(self.qnetwork_local)
if torch.cuda.is_available():
print("using GPUs!")
net.cuda()
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
"*** YOUR CODE HERE ***"
# target net update
# Get max predicted Q values (for next states) from target model
qs_local = self.qnetwork_local.forward(states)
qsa_local = qs_local[torch.arange(BATCH_SIZE, dtype=torch.long),
actions.reshape(BATCH_SIZE)]
Q_expected = qsa_local.reshape((BATCH_SIZE, 1))
qs_target = self.qnetwork_target.forward(next_states)
_, qsa_local_argmax_a = torch.max(
qs_local, dim=1) #using the greedy policy (q-learning)
qsa_target = qs_target[torch.arange(BATCH_SIZE, dtype=torch.long),
qsa_local_argmax_a.reshape(BATCH_SIZE)]
qsa_target = qsa_target * (
1 - dones.reshape(BATCH_SIZE)
) #target qsa value is zero when episode is complete
qsa_target = qsa_target.reshape((BATCH_SIZE, 1))
Q_targets = rewards + gamma * qsa_target
# Compute loss
loss = F.mse_loss(Q_expected, Q_targets)
#logger.info('mse: {}'.format(delta))
# Minimize the loss
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step() # evolutionary step - increase survival chances
#logger.info('avg reward: {} mse:{}'.format(delta, np.mean(experiences.rewards())))
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size, seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size, seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBufferWithPriority(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences_with_index = self.memory.sample()
self.learn(experiences_with_index, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences_with_index, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences_with_index (Tuple[torch.Variable]): tuple of (s, a, r, s', done, index, weightsIS) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones, index, weightsIS = experiences_with_index
## TODO: compute and minimize the loss
# Get max predicted Q values (for next states) from target model
### Regular DQN
# Q_targets_next = self.qnetwork_target.forward(next_states).detach().max(1)[0].unsqueeze(1)
### Double DQN
with torch.no_grad():
estimated_action = self.qnetwork_local(next_states).argmax(dim=1, keepdim=True)
Q_targets_next = self.qnetwork_target.forward(next_states).gather(1, estimated_action)
# Compute Q targets for current states
Q_targets = rewards + (gamma * Q_targets_next * (1 - dones))
# Get expected Q values from local model
Q_expected = self.qnetwork_local.forward(states).gather(1, actions)
# Compute importance-sampling weight
# Compute loss
loss_fn = nn.MSELoss(reduce=False)
loss = loss_fn(Q_expected, Q_targets)
weighted_loss = torch.sum(torch.from_numpy(weightsIS).float().to(device) * loss)
# Update priority according to TD error
self.memory.update_priority(list(loss.detach().cpu().numpy().squeeze()**ALPHA+EPS), index)
# Minimize the loss
self.optimizer.zero_grad()
weighted_loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
""" Agent used to interact with and learns from the environment """
def __init__(self, state_size, action_size, config):
""" Initialize an Agent object """
self.state_size = state_size
self.action_size = action_size
self.config = config
# logging for this class
self.logger = logging.getLogger(self.__class__.__name__)
# gpu support
self.device = pick_device(config, self.logger)
## Q-Networks
self.qnetwork_local = QNetwork(state_size, action_size, config).to(self.device)
self.qnetwork_target = QNetwork(state_size, action_size, config).to(self.device)
## Get optimizer for local network
self.optimizer = getattr(optim, config["optimizer"]["optimizer_type"])(
self.qnetwork_local.parameters(),
betas=tuple(config["optimizer"]["betas"]),
**config["optimizer"]["optimizer_params"])
## Replay memory
self.memory = ReplayBuffer(
config=config,
action_size=action_size,
buffer_size=int(config["DQN"]["buffer_size"]),
batch_size=config["trainer"]["batch_size"]
)
## Initialize time step (for update every `update_every` steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every `update_every` time steps
self.t_step = (self.t_step + 1) % self.config["DQN"]["update_every"]
if (self.t_step == 0):
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > self.config["trainer"]["batch_size"]:
experiences = self.memory.sample()
self.learn(experiences, self.config["DQN"]["gamma"])
def act(self, state, epsilon):
""" Returns actions for given state as per current policy """
# pdb.set_trace()
# Convert state to tensor
state = torch.from_numpy(state).float().unsqueeze(0).to(self.device)
## Evaluation mode
self.qnetwork_local.eval()
with torch.no_grad():
# Forward pass of local qnetwork
action_values = self.qnetwork_local.forward(state)
## Training mode
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > epsilon:
# Choose the best action (exploitation)
return np.argmax(action_values.cpu().data.numpy())
else:
# Choose random action (exploration)
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
""" Update value parameters using given batch of experience tuples """
states, actions, rewards, next_states, dones = experiences
## TD target
# Get max predicted Q-values (for next states) from target model
# Q_targets_next = torch.argmax(self.qnetwork_target(next_states).detach(), dim=1).unsqueeze(1)
Q_targets_next = self.qnetwork_target(next_states).detach().max(1)[0].unsqueeze(1)
Q_targets_next = Q_targets_next.type(torch.FloatTensor)
# Compute Q-targets for current states
Q_targets = rewards + (gamma * Q_targets_next * (1 - dones))
## old value
# Get expected Q-values from local model
Q_expected = torch.gather(self.qnetwork_local(states), dim=1, index=actions)
# Compute loss
loss = F.mse_loss(Q_expected, Q_targets)
# Minimize loss
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# update target network with a soft update
self.soft_update(self.qnetwork_local, self.qnetwork_target, self.config["DQN"]["tau"])
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self,
state_size,
action_size,
seed,
fc1_units=64,
fc2_units=64,
fc3_units=None,
double_q=False):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
self.double_q = double_q
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size, seed,
fc1_units, fc2_units,
fc3_units).to(device)
self.qnetwork_target = QNetwork(state_size, action_size, seed,
fc1_units, fc2_units,
fc3_units).to(device)
if torch.cuda.is_available():
self.qnetwork_local.cuda()
self.qnetwork_target.cuda()
else:
self.qnetwork_local.cpu()
self.qnetwork_target.cpu()
self.optimizer = optim.Adam(self.qnetwork_local.parameters(),
lr=LR,
weight_decay=WD)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def get_action(self, state, eps=0.):
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
with torch.no_grad():
output = self.qnetwork_local.forward(state)
action_values = self.qnetwork_local.forward(state)
if random.random() <= eps:
return np.random.choice(np.arange(self.action_size))
else:
return output.argmax().item()
def learn(self, experiences, gamma):
states, actions, rewards, next_states, dones = experiences
# double q learning
argmax_a = self.qnetwork_local.forward(next_states).detach().argmax(
dim=1).unsqueeze(dim=1)
a_val = self.qnetwork_target.forward(next_states).detach()
Q_targets_next = a_val.gather(1, argmax_a)
Q_targets = rewards + GAMMA * Q_targets_next
Q_expected = self.qnetwork_local.forward(states).gather(1, actions)
loss = F.mse_loss(Q_expected, Q_targets)
# Minimize the loss
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed=0):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Initialize both the target and the local Q networks
self.qnetwork_local = QNetwork(state_size, action_size).to(device)
self.qnetwork_target = QNetwork(state_size, action_size).to(device)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, MINIBATCH_SIZE, seed)
# The Optimizer used is Adam
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LEARNING_RATE)
# Initialize time step (for updating every UPDATE_EVERY steps)
# Used to determine when the agent starts learning
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# check if there are enough examples in memory
if len(self.memory) > MINIBATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
# Aquire an action by passing the current state to the local network
action_values = self.qnetwork_local.forward(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
# Get max predicted Q values (for next states) from target model
# running forward on the target network on the set of experiences
Q_targets_next = self.qnetwork_target.forward(next_states).detach().max(1)[0].unsqueeze(1)
# Compute Q targets for current states
Q_targets = rewards + (gamma * Q_targets_next * (1 - dones))
# Get expected Q values from local model
Q_expected = self.qnetwork_local.forward(states).gather(1, actions)
# Compute loss
loss = F.mse_loss(Q_expected, Q_targets)
# Minimize the loss
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
self.soft_updatee(self.qnetwork_local, self.qnetwork_target, TAU)
def hard_update(self, local_model, target_model):
"""Hard update the bias and the weights from the local Network to the target network"""
for target_param, local_param in zip(target_model.parameters(), local_model.parameters()):
target_param.data.copy_(local_param.data)
def soft_updatee(self, local_model, target_model, tau):
"""Soft update the weights and biases from the local Network to the target network using the update factor tau"""
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 save_weights(self, path='./p1_weights'):
"""Save the trained weights of the current local Q network‚"""
torch.save(self.qnetwork_local.state_dict(), path)
def load_saved_weights(self, path='./p1_weights'):
""""
Load the weights to the local and target Q network
"""
self.qnetwork_local.load_state_dict(torch.load(path))
self.qnetwork_local.eval()
self.qnetwork_target.load_state_dict(torch.load(path))
self.qnetwork_target.eval()
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(
state) # same as self.qnetwork_local.forward(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Tensor]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
# "*** YOUR CODE HERE ***"
qs_local = self.qnetwork_local.forward(states)
qsa_local = qs_local[torch.arange(BATCH_SIZE, dtype=torch.long),
actions.reshape(BATCH_SIZE)]
qsa_local = qsa_local.reshape((BATCH_SIZE, 1))
# print(qsa_local.shape)
# # DQN Target
# qs_target = self.qnetwork_target.forward(next_states)
# qsa_target, _ = torch.max(qs_target, dim=1) #using the greedy policy (q-learning)
# qsa_target = qsa_target * (1 - dones.reshape(BATCH_SIZE)) #target qsa value is zero when episode is complete
# qsa_target = qsa_target.reshape((BATCH_SIZE,1))
# TD_target = rewards + gamma * qsa_target
# #print(qsa_target.shape, TD_target.shape, rewards.shape)
# # Double DQN Target ver 1
# qs_target = self.qnetwork_target.forward(next_states)
# if random.random() > 0.5:
# _, qsa_target_argmax_a = torch.max(qs_target, dim=1) #using the greedy policy (q-learning)
# qsa_target = qs_target[torch.arange(BATCH_SIZE, dtype=torch.long), qsa_target_argmax_a.reshape(BATCH_SIZE)]
# else:
# _, qsa_local_argmax_a = torch.max(qs_local, dim=1) #using the greedy policy (q-learning)
# #qsa_target = qs_target[torch.arange(BATCH_SIZE, dtype=torch.long), qsa_local_argmax_a.reshape(BATCH_SIZE)]
# ##qsa_target = qs_local[torch.arange(BATCH_SIZE, dtype=torch.long), qsa_local_argmax_a.reshape(BATCH_SIZE)]
# qsa_target = qsa_target * (1 - dones.reshape(BATCH_SIZE)) #target qsa value is zero when episode is complete
# qsa_target = qsa_target.reshape((BATCH_SIZE,1))
# TD_target = rewards + gamma * qsa_target
# Double DQN Target ver 2 (based upon double dqn paper)
qs_target = self.qnetwork_target.forward(next_states)
_, qsa_local_argmax_a = torch.max(
qs_local, dim=1) # using the greedy policy (q-learning)
qsa_target = qs_target[torch.arange(BATCH_SIZE, dtype=torch.long),
qsa_local_argmax_a.reshape(BATCH_SIZE)]
qsa_target = qsa_target * (
1 - dones.reshape(BATCH_SIZE)
) # target qsa value is zero when episode is complete
qsa_target = qsa_target.reshape((BATCH_SIZE, 1))
TD_target = rewards + gamma * qsa_target
# print(qsa_target.shape, TD_target.shape, rewards.shape)
# #Udacity's approach
# # Get max predicted Q values (for next states) from target model
# Q_targets_next = self.qnetwork_target(next_states).detach().max(1)[0].unsqueeze(1)
# # Compute Q targets for current states
# TD_target = rewards + (gamma * Q_targets_next * (1 - dones))
# # Get expected Q values from local model
# qsa_local = self.qnetwork_local(states).gather(1, actions)
# diff = qsa_local - TD_target
# loss = torch.matmul(torch.transpose(diff, dim0=0, dim1=1), diff) #loss is now a scalar
loss = F.mse_loss(
qsa_local, TD_target) # much faster than the above loss function
# print(loss)
# minimize the loss
self.optimizer.zero_grad() # clears the gradients
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
"""Interacts with the environment , act and learn from the environment"""
def __init__(self, state_size, action_size, seed):
"""Initializes Agent object ,
1. agent variables,
2. local and target QNetworks,
3. Optimizer,
4. Replay Buffer"""
self.state_size = state_size
self.action_size = action_size
self.seed = torch.manual_seed(seed)
self.t_step = 0
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
def act(self, state, eps=eps):
"""To read state , pass it through local network and return action values as per the given policy.
Then from action values , based on eps gives argmax or chooses a random action from action values"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local.forward(state)
self.qnetwork_local.train()
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(1, self.action_size))
def step(self, state, action, reward, next_state, done):
"""Perform a step which consists of,
1. Add into Replay Buffer
2. Learn
"""
self.memory.add(state, action, reward, next_state, done)
self.t_step = (self.t_step + 1) % LEARN_EVERY
if self.t_step == 0:
if self.memory.getlength > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def learn(self, experiences, GAMMA):
"""Calculate the MSE based on Expected Q value and Target Q value.
Use optimizer to learn from MSE and calculate target weights and then update those weights in the target Q network"""
states, actions, rewards, next_states, done = experiences
Q_expected = self.qnetwork_local(states).gather(1, actions)
Q_targets_next = self.qnetwork_target(next_states).detach().max(
0)[1].unsqueeze(1)
Q_targets = rewards + (GAMMA * Q_targets_next * (1 - done))
loss = F.mse_loss(Q_expected, Q_targets)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
def soft_update(self, local_model, target_model, tau):
"""Perform inplace copy of target parameters based on Tau"""
for local_params, target_params in zip(local_model.parameters(),
target_model.parameters()):
target_params.data.copy_(tau * local_params.data +
(1 - tau) * target_params.data)
class Agent(object):
def __init__(self, state_size, action_size, mem_length=100000, ddqn=True):
self.gamma = 0.99
self.batch_size = 64
self.action_size = action_size
self.ddqn = ddqn
self.device = torch.device(
"cuda:0" if torch.cuda.is_available() else "cpu")
if ddqn:
self.model = DuelingQNetwork(state_size,
action_size).to(self.device)
self.target_model = DuelingQNetwork(state_size,
action_size).to(self.device)
self.optimizer = optim.Adam(self.model.parameters(), lr=5e-4)
self.experience = self.ddqn_experience
else:
self.model = QNetwork(state_size, action_size).to(self.device)
self.optimizer = optim.Adam(self.model.parameters(), lr=5e-4)
self.experience = self.dqn_experience
# replay memory
self.memory = deque(maxlen=mem_length)
def act(self, state, eps=0):
# epsilon greedy
if random.random() < eps:
return random.choice(np.arange(self.action_size))
# state to predict action from
state = torch.FloatTensor(state).unsqueeze(0).to(self.device)
self.model.eval()
with torch.no_grad():
action_values = self.model(state)
self.model.train()
return np.argmax(action_values.cpu().data.numpy())
def ddqn_experience(self, state, action, reward, next_state, done):
self.memory.append((state, action, reward, next_state, done))
if len(self.memory) < self.batch_size:
return
# get random batch
states, actions, rewards, next_states, terminals = self.get_batch()
# Get expected Q values from local model
expected = self.model(states).gather(1, actions)
Q = self.model(next_states).detach()
# Get max predicted Q values (for next states) from target model
targets_next = self.target_model(next_states).detach()
targets_next = targets_next.gather(1, Q.max(1)[1].unsqueeze(1))
# Compute Q targets for current states
targets = rewards + (self.gamma * targets_next * (1 - terminals))
# compute loss
loss = functional.mse_loss(expected, targets)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# update target network
lr = 0.001
for target_param, primary_param in zip(self.target_model.parameters(),
self.model.parameters()):
target_param.data.copy_(lr * primary_param.data +
(1 - lr) * target_param.data)
def dqn_experience(self, state, action, reward, next_state, done):
self.memory.append((state, action, reward, next_state, done))
if len(self.memory) < self.batch_size:
return
# get random batch
states, actions, rewards, next_states, terminals = self.get_batch()
Q = self.model.forward(states)
Q = Q.gather(1, actions).squeeze(1)
next_Q = self.model.forward(next_states)
max_next_Q = torch.max(next_Q, 1)[0]
expected = rewards.squeeze(1) + self.gamma * max_next_Q
# update model
loss = functional.mse_loss(Q, expected)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
def get_batch(self):
experiences = np.array(random.sample(self.memory, k=self.batch_size))
experiences = [np.vstack(experiences[:, i]) for i in range(5)]
# convert data to tensors
states = torch.FloatTensor(experiences[0]).to(self.device)
actions = torch.LongTensor(experiences[1]).to(self.device)
rewards = torch.FloatTensor(experiences[2]).to(self.device)
next_states = torch.FloatTensor(experiences[3]).to(self.device)
terminals = torch.FloatTensor(experiences[4].astype(np.uint8)).to(
self.device)
return states, actions, rewards, next_states, terminals
class Agent():
def __init__(self, state_size, action_size, seed):
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
self.t_step = 0
def step(self, state, action, reward, next_state, done, priority, B_P):
self.memory.add(state, action, reward, next_state, done, priority)
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample(B_P)
self.learn(experiences, GAMMA)
def priority(self, states, actions, rewards, next_states):
if len(states.shape) == 1:
# only a single experience tuple to evaluate
# need to format variables accordingly:
states = torch.from_numpy(states).float().unsqueeze(0).to(device)
next_states = torch.from_numpy(next_states).float().unsqueeze(
0).to(device)
rewards = torch.tensor([[rewards]], dtype=torch.float).to(
device) # scalar value
actions = torch.tensor([[actions]], dtype=torch.uint8).to(
device) # scalar value
action_local = self.qnetwork_local.forward(next_states).argmax(1)
max_q = self.qnetwork_target.forward(next_states)[
np.arange(action_local.shape[0]), action_local]
delta = (rewards.squeeze() + GAMMA * max_q) - self.qnetwork_local(
states)[np.arange(actions.shape[0]),
actions.byte().squeeze().cpu().numpy()]
priority = torch.abs(delta) + E_p
return priority.squeeze().tolist()
def act(self, state, eps=0.):
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
states, actions, rewards, next_states, dones, weights, experience_indices = experiences
Q_targets_next = self.qnetwork_target(next_states).detach().max(
1)[0].unsqueeze(1)
Q_targets = rewards + (gamma * Q_targets_next * (1 - dones))
Q_expected = self.qnetwork_local(states).gather(1, actions)
loss = WEightedMSE(Q_expected, Q_targets, weights)
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
# ------------------- update priorities in the replay buffer ------------------- #
new_priorities = self.priority(states, actions, rewards, next_states)
for count, idx in enumerate(experience_indices):
self.memory.memory[idx] = self.memory.memory[idx]._replace(
priority=new_priorities[count])
def soft_update(self, local_model, target_model, tau):
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)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def priority(self, states, actions, rewards, next_states):
if len(states.shape) == 1:
# only a single experience tuple to evaluate
# need to format variables accordingly:
states = torch.from_numpy(states).float().unsqueeze(0).to(device)
next_states = torch.from_numpy(next_states).float().unsqueeze(
0).to(device)
rewards = torch.tensor([[rewards]], dtype=torch.float).to(
device) # scalar value
actions = torch.tensor([[actions]], dtype=torch.uint8).to(
device) # scalar value
action_local = self.qnetwork_local.forward(next_states).argmax(1)
max_q = self.qnetwork_target.forward(next_states)[
np.arange(action_local.shape[0]), action_local]
delta = (rewards.squeeze() + GAMMA * max_q) - self.qnetwork_local(
states)[np.arange(actions.shape[0]),
actions.byte().squeeze().cpu().numpy()]
priority = torch.abs(delta) + E_PRIORITY
return priority.squeeze().tolist()
def step(self, state, action, reward, next_state, done, priority,
b_priority):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done, priority)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample(
b_priority) # needs b_priority to compute weights
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones, weights, experience_indices = experiences
## TODO: compute and minimize the loss
"*** YOUR CODE HERE ***"
actions_local = self.qnetwork_local.forward(next_states).argmax(1)
max_q_values = self.qnetwork_target.forward(next_states)[
np.arange(actions_local.shape[0]), actions_local]
td_target = rewards.squeeze() + gamma * max_q_values * (
1 - dones.squeeze())
predicted_q_values = self.qnetwork_local.forward(states)
predicted_q_values = predicted_q_values[
np.arange(predicted_q_values.shape[0]),
actions.squeeze()]
self.optimizer.zero_grad(
) # must zero the gradients each time, otherwise they get summed
# Forward and backward passes
loss = WeightedMSE(predicted_q_values, td_target, weights)
loss.backward() # backward pass to compute the gradients
self.optimizer.step(
) # take a step using the learning rate and computed gradient
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
# ------------------- update priorities in the replay buffer ------------------- #
new_priorities = self.priority(states, actions, rewards, next_states)
for count, idx in enumerate(experience_indices):
self.memory.memory[idx] = self.memory.memory[idx]._replace(
priority=new_priorities[count])
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)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
hidden_layers = [128,64]
self.qnetwork_local = QNetwork(state_size, action_size, hidden_layers, seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size, hidden_layers, seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
#Initialising target and local environment with same weights
self.hard_update(self.qnetwork_local,self.qnetwork_target)
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
def update(self):
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if np.random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
"*** YOUR CODE HERE ***"
max_actions = self.qnetwork_local.forward(next_states).detach().max(1)[1].unsqueeze(1)
output_target = self.qnetwork_target.forward(next_states).gather(1,max_actions)
td_target = rewards + gamma*(output_target*(1-dones))
output_local= self.qnetwork_local(states).gather(1, actions)
loss = F.mse_loss(output_local,td_target)
self.optimizer.zero_grad()
loss.backward()
torch.nn.utils.clip_grad_norm_(self.qnetwork_local.parameters(), 1)
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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 hard_update(self,local_model,target_model):
for target_param,local_param in zip(target_model.parameters(),local_model.parameters()):
target_param.data.copy_(local_param)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed, use_ddqn=True):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
self.use_ddqn = use_ddqn
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
self.t_step = (self.t_step + 1) % UPDATE_EVERY
if self.t_step == 0:
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
if self.use_ddqn: # Use double dqn for training if selected
self.learn_ddqn(experiences, GAMMA)
else:
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
# compute and minimize the loss
qvalue_target = self.qnetwork_target.forward(next_states).detach().max(
1)[0].unsqueeze(1)
y = rewards + gamma * qvalue_target * (1 - dones)
qvalue = self.qnetwork_local.forward(states).gather(1, actions)
#print("Best actions:")
#print(qvalue)
loss = F.mse_loss(y, qvalue)
# Optimize the model
self.optimizer.zero_grad()
loss.backward()
#for param in self.qnetwork_local.parameters():
# param.grad.data.clamp_(-1, 1)
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
def learn_ddqn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples uaing double dqn method.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
# Get best actions from local model to use in the double DQN
best_actions_local = self.qnetwork_local(next_states).detach().argmax(
dim=1).unsqueeze(1)
# Get predicted Q values (for next states) from target model using actions selected from double DQN using local model
qvalue_target = self.qnetwork_target(next_states).detach().gather(
1, best_actions_local)
# compute and minimize the loss
y = rewards + gamma * qvalue_target * (1 - dones)
qvalue = self.qnetwork_local.forward(states).gather(1, actions)
#print("Best actions:")
#print(qvalue)
loss = F.mse_loss(y, qvalue)
# Optimize the model
self.optimizer.zero_grad()
loss.backward()
#for param in self.qnetwork_local.parameters():
# param.grad.data.clamp_(-1, 1)
self.optimizer.step()
# ------------------- update target network ------------------- #
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
class Agent():
"""Interacts with and learns from the environment."""
def __init__(self, state_size, action_size, seed):
"""Initialize an Agent object.
Params
======
state_size (int): dimension of each state
action_size (int): dimension of each action
seed (int): random seed
"""
self.state_size = state_size
self.action_size = action_size
self.seed = random.seed(seed)
# Q-Network
self.qnetwork_local = QNetwork(state_size, action_size,
seed).to(device)
self.qnetwork_target = QNetwork(state_size, action_size,
seed).to(device)
self.optimizer = optim.Adam(self.qnetwork_local.parameters(), lr=LR)
# Replay memory
self.memory = ReplayBuffer(action_size, BUFFER_SIZE, BATCH_SIZE, seed)
# Initialize time step (for updating every UPDATE_EVERY steps)
self.t_step = 0
def step(self, state, action, reward, next_state, done):
# Save experience in replay memory
self.memory.add(state, action, reward, next_state, done)
# Learn every UPDATE_EVERY time steps.
#self.t_step = (self.t_step + 1) % UPDATE_EVERY
#if self.t_step == 0:
self.t_step += 1
# If enough samples are available in memory, get random subset and learn
if len(self.memory) > BATCH_SIZE:
experiences = self.memory.sample()
self.learn(experiences, GAMMA)
def act(self, state, eps=0.):
"""Returns actions for given state as per current policy.
Params
======
state (array_like): current state
eps (float): epsilon, for epsilon-greedy action selection
"""
state = torch.from_numpy(state).float().unsqueeze(0).to(device)
self.qnetwork_local.eval()
with torch.no_grad():
action_values = self.qnetwork_local(state)
self.qnetwork_local.train()
# Epsilon-greedy action selection
if random.random() > eps:
return np.argmax(action_values.cpu().data.numpy())
else:
return random.choice(np.arange(self.action_size))
def learn(self, experiences, gamma):
"""Update value parameters using given batch of experience tuples.
Params
======
experiences (Tuple[torch.Variable]): tuple of (s, a, r, s', done) tuples
gamma (float): discount factor
"""
states, actions, rewards, next_states, dones = experiences
## TODO: compute and minimize the loss
# train loop
# states and next_states (batch_size x num_states)
# actions and rewards (batch_size x 1)
# forward pass
# use local network to compute q_est(s,w)[action]
ps_local = self.qnetwork_local.forward(states).gather(1, actions)
# use target network compute r + g*max(q_est[s',a, w-]), this tensor should be detached from backward computations
ps_target = rewards + gamma * (
1 - dones) * self.qnetwork_target.forward(
next_states).detach().max(dim=1)[0].view(-1, 1)
# compute loss
loss = F.mse_loss(ps_local, ps_target)
# backward pass
self.optimizer.zero_grad()
loss.backward()
self.optimizer.step()
# ------------------- update target network ------------------- #
if (self.t_step % UPDATE_EVERY) == 0:
self.soft_update(self.qnetwork_local, self.qnetwork_target, TAU)
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)
