def __init__(
self,
observation_space,
action_space,
actor_class=QActor,
actor_kwargs={},
actor_param_class=ParamActor,
actor_param_kwargs={},
epsilon_initial=1.0,
epsilon_final=0.05,
epsilon_steps=10000,
batch_size=64,
gamma=0.99,
tau_actor=0.01, # Polyak averaging factor for copying target weights
tau_actor_param=0.001,
replay_memory_size=1000000,
learning_rate_actor=0.0001,
learning_rate_actor_param=0.00001,
initial_memory_threshold=0,
use_ornstein_noise=False, # if false, uses epsilon-greedy with uniform-random action-parameter exploration
loss_func=F.mse_loss, # F.mse_loss
clip_grad=10,
inverting_gradients=False,
zero_index_gradients=False,
indexed=False,
weighted=False,
average=False,
random_weighted=False,
device="cuda" if torch.cuda.is_available() else "cpu",
seed=None):
super(PDQNAgent, self).__init__(observation_space, action_space)
self.device = torch.device(device)
self.num_actions = self.action_space.spaces[0].n
self.action_parameter_sizes = np.array([
self.action_space.spaces[i].shape[0]
for i in range(1, self.num_actions + 1)
])
self.action_parameter_size = int(self.action_parameter_sizes.sum())
self.action_max = torch.from_numpy(np.ones(
(self.num_actions, ))).float().to(device)
self.action_min = -self.action_max.detach()
self.action_range = (self.action_max - self.action_min).detach()
print([
self.action_space.spaces[i].high
for i in range(1, self.num_actions + 1)
])
self.action_parameter_max_numpy = np.concatenate([
self.action_space.spaces[i].high
for i in range(1, self.num_actions + 1)
]).ravel()
self.action_parameter_min_numpy = np.concatenate([
self.action_space.spaces[i].low
for i in range(1, self.num_actions + 1)
]).ravel()
self.action_parameter_range_numpy = (self.action_parameter_max_numpy -
self.action_parameter_min_numpy)
self.action_parameter_max = torch.from_numpy(
self.action_parameter_max_numpy).float().to(device)
self.action_parameter_min = torch.from_numpy(
self.action_parameter_min_numpy).float().to(device)
self.action_parameter_range = torch.from_numpy(
self.action_parameter_range_numpy).float().to(device)
self.epsilon = epsilon_initial
self.epsilon_initial = epsilon_initial
self.epsilon_final = epsilon_final
self.epsilon_steps = epsilon_steps
self.indexed = indexed
self.weighted = weighted
self.average = average
self.random_weighted = random_weighted
assert (weighted ^ average ^ random_weighted
) or not (weighted or average or random_weighted)
self.action_parameter_offsets = self.action_parameter_sizes.cumsum()
self.action_parameter_offsets = np.insert(
self.action_parameter_offsets, 0, 0)
self.batch_size = batch_size
self.gamma = gamma
self.replay_memory_size = replay_memory_size
self.initial_memory_threshold = initial_memory_threshold
self.learning_rate_actor = learning_rate_actor
self.learning_rate_actor_param = learning_rate_actor_param
self.inverting_gradients = inverting_gradients
self.tau_actor = tau_actor
self.tau_actor_param = tau_actor_param
self._step = 0
self._episode = 0
self.updates = 0
self.clip_grad = clip_grad
self.zero_index_gradients = zero_index_gradients
self.np_random = None
self.seed = seed
self._seed(seed)
self.use_ornstein_noise = use_ornstein_noise
self.noise = OrnsteinUhlenbeckActionNoise(
self.action_parameter_size,
random_machine=self.np_random,
mu=0.,
theta=0.15,
sigma=0.0001) #, theta=0.01, sigma=0.01)
print(self.num_actions + self.action_parameter_size)
self.replay_memory = Memory(replay_memory_size,
observation_space.shape,
(1 + self.action_parameter_size, ),
next_actions=False)
self.actor = actor_class(self.observation_space.shape[0],
self.num_actions, self.action_parameter_size,
**actor_kwargs).to(device)
self.actor_target = actor_class(self.observation_space.shape[0],
self.num_actions,
self.action_parameter_size,
**actor_kwargs).to(device)
hard_update_target_network(self.actor, self.actor_target)
self.actor_target.eval()
self.actor_param = actor_param_class(self.observation_space.shape[0],
self.num_actions,
self.action_parameter_size,
**actor_param_kwargs).to(device)
self.actor_param_target = actor_param_class(
self.observation_space.shape[0], self.num_actions,
self.action_parameter_size, **actor_param_kwargs).to(device)
hard_update_target_network(self.actor_param, self.actor_param_target)
self.actor_param_target.eval()
self.loss_func = loss_func # l1_smooth_loss performs better but original paper used MSE
# Original DDPG paper [Lillicrap et al. 2016] used a weight decay of 0.01 for Q (critic)
# but setting weight_decay=0.01 on the critic_optimiser seems to perform worse...
# using AMSgrad ("fixed" version of Adam, amsgrad=True) doesn't seem to help either...
self.actor_optimiser = optim.Adam(
self.actor.parameters(),
lr=self.learning_rate_actor) #, betas=(0.95, 0.999))
self.actor_param_optimiser = optim.Adam(
self.actor_param.parameters(), lr=self.learning_rate_actor_param
) #, betas=(0.95, 0.999)) #, weight_decay=critic_l2_reg)
class PDQNAgent(Agent):
"""
DDPG actor-critic agent for parameterised action spaces
[Hausknecht and Stone 2016]
"""
NAME = "P-DQN Agent"
def __init__(
self,
observation_space,
action_space,
actor_class=QActor,
actor_kwargs={},
actor_param_class=ParamActor,
actor_param_kwargs={},
epsilon_initial=1.0,
epsilon_final=0.05,
epsilon_steps=10000,
batch_size=64,
gamma=0.99,
tau_actor=0.01, # Polyak averaging factor for copying target weights
tau_actor_param=0.001,
replay_memory_size=1000000,
learning_rate_actor=0.0001,
learning_rate_actor_param=0.00001,
initial_memory_threshold=0,
use_ornstein_noise=False, # if false, uses epsilon-greedy with uniform-random action-parameter exploration
loss_func=F.mse_loss, # F.mse_loss
clip_grad=10,
inverting_gradients=False,
zero_index_gradients=False,
indexed=False,
weighted=False,
average=False,
random_weighted=False,
device="cuda" if torch.cuda.is_available() else "cpu",
seed=None):
super(PDQNAgent, self).__init__(observation_space, action_space)
self.device = torch.device(device)
self.num_actions = self.action_space.spaces[0].n
self.action_parameter_sizes = np.array([
self.action_space.spaces[i].shape[0]
for i in range(1, self.num_actions + 1)
])
self.action_parameter_size = int(self.action_parameter_sizes.sum())
self.action_max = torch.from_numpy(np.ones(
(self.num_actions, ))).float().to(device)
self.action_min = -self.action_max.detach()
self.action_range = (self.action_max - self.action_min).detach()
print([
self.action_space.spaces[i].high
for i in range(1, self.num_actions + 1)
])
self.action_parameter_max_numpy = np.concatenate([
self.action_space.spaces[i].high
for i in range(1, self.num_actions + 1)
]).ravel()
self.action_parameter_min_numpy = np.concatenate([
self.action_space.spaces[i].low
for i in range(1, self.num_actions + 1)
]).ravel()
self.action_parameter_range_numpy = (self.action_parameter_max_numpy -
self.action_parameter_min_numpy)
self.action_parameter_max = torch.from_numpy(
self.action_parameter_max_numpy).float().to(device)
self.action_parameter_min = torch.from_numpy(
self.action_parameter_min_numpy).float().to(device)
self.action_parameter_range = torch.from_numpy(
self.action_parameter_range_numpy).float().to(device)
self.epsilon = epsilon_initial
self.epsilon_initial = epsilon_initial
self.epsilon_final = epsilon_final
self.epsilon_steps = epsilon_steps
self.indexed = indexed
self.weighted = weighted
self.average = average
self.random_weighted = random_weighted
assert (weighted ^ average ^ random_weighted
) or not (weighted or average or random_weighted)
self.action_parameter_offsets = self.action_parameter_sizes.cumsum()
self.action_parameter_offsets = np.insert(
self.action_parameter_offsets, 0, 0)
self.batch_size = batch_size
self.gamma = gamma
self.replay_memory_size = replay_memory_size
self.initial_memory_threshold = initial_memory_threshold
self.learning_rate_actor = learning_rate_actor
self.learning_rate_actor_param = learning_rate_actor_param
self.inverting_gradients = inverting_gradients
self.tau_actor = tau_actor
self.tau_actor_param = tau_actor_param
self._step = 0
self._episode = 0
self.updates = 0
self.clip_grad = clip_grad
self.zero_index_gradients = zero_index_gradients
self.np_random = None
self.seed = seed
self._seed(seed)
self.use_ornstein_noise = use_ornstein_noise
self.noise = OrnsteinUhlenbeckActionNoise(
self.action_parameter_size,
random_machine=self.np_random,
mu=0.,
theta=0.15,
sigma=0.0001) #, theta=0.01, sigma=0.01)
print(self.num_actions + self.action_parameter_size)
self.replay_memory = Memory(replay_memory_size,
observation_space.shape,
(1 + self.action_parameter_size, ),
next_actions=False)
self.actor = actor_class(self.observation_space.shape[0],
self.num_actions, self.action_parameter_size,
**actor_kwargs).to(device)
self.actor_target = actor_class(self.observation_space.shape[0],
self.num_actions,
self.action_parameter_size,
**actor_kwargs).to(device)
hard_update_target_network(self.actor, self.actor_target)
self.actor_target.eval()
self.actor_param = actor_param_class(self.observation_space.shape[0],
self.num_actions,
self.action_parameter_size,
**actor_param_kwargs).to(device)
self.actor_param_target = actor_param_class(
self.observation_space.shape[0], self.num_actions,
self.action_parameter_size, **actor_param_kwargs).to(device)
hard_update_target_network(self.actor_param, self.actor_param_target)
self.actor_param_target.eval()
self.loss_func = loss_func # l1_smooth_loss performs better but original paper used MSE
# Original DDPG paper [Lillicrap et al. 2016] used a weight decay of 0.01 for Q (critic)
# but setting weight_decay=0.01 on the critic_optimiser seems to perform worse...
# using AMSgrad ("fixed" version of Adam, amsgrad=True) doesn't seem to help either...
self.actor_optimiser = optim.Adam(
self.actor.parameters(),
lr=self.learning_rate_actor) #, betas=(0.95, 0.999))
self.actor_param_optimiser = optim.Adam(
self.actor_param.parameters(), lr=self.learning_rate_actor_param
) #, betas=(0.95, 0.999)) #, weight_decay=critic_l2_reg)
def __str__(self):
desc = super().__str__() + "\n"
desc += "Actor Network {}\n".format(self.actor) + \
"Param Network {}\n".format(self.actor_param) + \
"Actor Alpha: {}\n".format(self.learning_rate_actor) + \
"Actor Param Alpha: {}\n".format(self.learning_rate_actor_param) + \
"Gamma: {}\n".format(self.gamma) + \
"Tau (actor): {}\n".format(self.tau_actor) + \
"Tau (actor-params): {}\n".format(self.tau_actor_param) + \
"Inverting Gradients: {}\n".format(self.inverting_gradients) + \
"Replay Memory: {}\n".format(self.replay_memory_size) + \
"Batch Size: {}\n".format(self.batch_size) + \
"Initial memory: {}\n".format(self.initial_memory_threshold) + \
"epsilon_initial: {}\n".format(self.epsilon_initial) + \
"epsilon_final: {}\n".format(self.epsilon_final) + \
"epsilon_steps: {}\n".format(self.epsilon_steps) + \
"Clip Grad: {}\n".format(self.clip_grad) + \
"Ornstein Noise?: {}\n".format(self.use_ornstein_noise) + \
"Zero Index Grads?: {}\n".format(self.zero_index_gradients) + \
"Seed: {}\n".format(self.seed)
return desc
def set_action_parameter_passthrough_weights(self,
initial_weights,
initial_bias=None):
passthrough_layer = self.actor_param.action_parameters_passthrough_layer
print(initial_weights.shape)
print(passthrough_layer.weight.data.size())
assert initial_weights.shape == passthrough_layer.weight.data.size()
passthrough_layer.weight.data = torch.Tensor(
initial_weights).float().to(self.device)
if initial_bias is not None:
print(initial_bias.shape)
print(passthrough_layer.bias.data.size())
assert initial_bias.shape == passthrough_layer.bias.data.size()
passthrough_layer.bias.data = torch.Tensor(
initial_bias).float().to(self.device)
passthrough_layer.requires_grad = False
passthrough_layer.weight.requires_grad = False
passthrough_layer.bias.requires_grad = False
hard_update_target_network(self.actor_param, self.actor_param_target)
def _seed(self, seed=None):
"""
NOTE: this will not reset the randomly initialised weights; use the seed parameter in the constructor instead.
:param seed:
:return:
"""
self.seed = seed
random.seed(seed)
np.random.seed(seed)
self.np_random = np.random.RandomState(seed=seed)
if seed is not None:
torch.manual_seed(seed)
if self.device == torch.device("cuda"):
torch.cuda.manual_seed(seed)
def _ornstein_uhlenbeck_noise(self, all_action_parameters):
""" Continuous action exploration using an Ornstein–Uhlenbeck process. """
return all_action_parameters.data.numpy() + (
self.noise.sample() * self.action_parameter_range_numpy)
def start_episode(self):
pass
def end_episode(self):
self._episode += 1
ep = self._episode
if ep < self.epsilon_steps:
self.epsilon = self.epsilon_initial - (self.epsilon_initial -
self.epsilon_final) * (
ep / self.epsilon_steps)
else:
self.epsilon = self.epsilon_final
def act(self, state):
with torch.no_grad():
state = torch.from_numpy(state).to(self.device)
all_action_parameters = self.actor_param.forward(state)
# Hausknecht and Stone [2016] use epsilon greedy actions with uniform random action-parameter exploration
rnd = self.np_random.uniform()
if rnd < self.epsilon:
action = self.np_random.choice(self.num_actions)
if not self.use_ornstein_noise:
all_action_parameters = torch.from_numpy(
np.random.uniform(self.action_parameter_min_numpy,
self.action_parameter_max_numpy))
else:
# select maximum action
Q_a = self.actor.forward(state.unsqueeze(0),
all_action_parameters.unsqueeze(0))
Q_a = Q_a.detach().cpu().data.numpy()
action = np.argmax(Q_a)
# add noise only to parameters of chosen action
all_action_parameters = all_action_parameters.cpu().data.numpy()
offset = np.array(
[self.action_parameter_sizes[i] for i in range(action)],
dtype=int).sum()
if self.use_ornstein_noise and self.noise is not None:
all_action_parameters[
offset:offset +
self.action_parameter_sizes[action]] += self.noise.sample(
)[offset:offset + self.action_parameter_sizes[action]]
action_parameters = all_action_parameters[
offset:offset + self.action_parameter_sizes[action]]
return action, action_parameters, all_action_parameters
def _zero_index_gradients(self, grad, batch_action_indices, inplace=True):
assert grad.shape[0] == batch_action_indices.shape[0]
grad = grad.cpu()
if not inplace:
grad = grad.clone()
with torch.no_grad():
ind = torch.zeros(self.action_parameter_size, dtype=torch.long)
for a in range(self.num_actions):
ind[self.action_parameter_offsets[a]:self.
action_parameter_offsets[a + 1]] = a
# ind_tile = np.tile(ind, (self.batch_size, 1))
ind_tile = ind.repeat(self.batch_size, 1).to(self.device)
actual_index = ind_tile != batch_action_indices[:, np.newaxis]
grad[actual_index] = 0.
return grad
def _invert_gradients(self, grad, vals, grad_type, inplace=True):
# 5x faster on CPU (for Soccer, slightly slower for Goal, Platform?)
if grad_type == "actions":
max_p = self.action_max
min_p = self.action_min
rnge = self.action_range
elif grad_type == "action_parameters":
max_p = self.action_parameter_max
min_p = self.action_parameter_min
rnge = self.action_parameter_range
else:
raise ValueError("Unhandled grad_type: '" + str(grad_type) + "'")
max_p = max_p.cpu()
min_p = min_p.cpu()
rnge = rnge.cpu()
grad = grad.cpu()
vals = vals.cpu()
assert grad.shape == vals.shape
if not inplace:
grad = grad.clone()
with torch.no_grad():
# index = grad < 0 # actually > but Adam minimises, so reversed (could also double negate the grad)
index = grad > 0
grad[index] *= (index.float() * (max_p - vals) / rnge)[index]
grad[~index] *= ((~index).float() * (vals - min_p) / rnge)[~index]
return grad
def step(self,
state,
action,
reward,
next_state,
next_action,
terminal,
time_steps=1):
act, all_action_parameters = action
self._step += 1
# self._add_sample(state, np.concatenate((all_actions.data, all_action_parameters.data)).ravel(), reward, next_state, terminal)
self._add_sample(state,
np.concatenate(
([act], all_action_parameters)).ravel(),
reward,
next_state,
np.concatenate(
([next_action[0]], next_action[1])).ravel(),
terminal=terminal)
if self._step >= self.batch_size and self._step >= self.initial_memory_threshold:
self._optimize_td_loss()
self.updates += 1
def _add_sample(self, state, action, reward, next_state, next_action,
terminal):
assert len(action) == 1 + self.action_parameter_size
self.replay_memory.append(state,
action,
reward,
next_state,
terminal=terminal)
def _optimize_td_loss(self):
if self._step < self.batch_size or self._step < self.initial_memory_threshold:
return
# Sample a batch from replay memory
states, actions, rewards, next_states, terminals = self.replay_memory.sample(
self.batch_size, random_machine=self.np_random)
states = torch.from_numpy(states).to(self.device)
actions_combined = torch.from_numpy(actions).to(
self.device) # make sure to separate actions and parameters
actions = actions_combined[:, 0].long()
action_parameters = actions_combined[:, 1:]
rewards = torch.from_numpy(rewards).to(self.device).squeeze()
next_states = torch.from_numpy(next_states).to(self.device)
terminals = torch.from_numpy(terminals).to(self.device).squeeze()
# ---------------------- optimize Q-network ----------------------
with torch.no_grad():
pred_next_action_parameters = self.actor_param_target.forward(
next_states)
pred_Q_a = self.actor_target(next_states,
pred_next_action_parameters)
Qprime = torch.max(pred_Q_a, 1, keepdim=True)[0].squeeze()
# Compute the TD error
target = rewards + (1 - terminals) * self.gamma * Qprime
# Compute current Q-values using policy network
q_values = self.actor(states, action_parameters)
y_predicted = q_values.gather(1, actions.view(-1, 1)).squeeze()
y_expected = target
loss_Q = self.loss_func(y_predicted, y_expected)
self.actor_optimiser.zero_grad()
loss_Q.backward()
if self.clip_grad > 0:
torch.nn.utils.clip_grad_norm_(self.actor.parameters(),
self.clip_grad)
self.actor_optimiser.step()
# ---------------------- optimize actor ----------------------
with torch.no_grad():
action_params = self.actor_param(states)
action_params.requires_grad = True
assert (self.weighted ^ self.average ^ self.random_weighted) or \
not (self.weighted or self.average or self.random_weighted)
Q = self.actor(states, action_params)
Q_val = Q
if self.weighted:
# approximate categorical probability density (i.e. counting)
counts = Counter(actions.cpu().numpy())
weights = torch.from_numpy(
np.array([
counts[a] / actions.shape[0]
for a in range(self.num_actions)
])).float().to(self.device)
Q_val = weights * Q
elif self.average:
Q_val = Q / self.num_actions
elif self.random_weighted:
weights = np.random.uniform(0, 1., self.num_actions)
weights /= np.linalg.norm(weights)
weights = torch.from_numpy(weights).float().to(self.device)
Q_val = weights * Q
if self.indexed:
Q_indexed = Q_val.gather(1, actions.unsqueeze(1))
Q_loss = torch.mean(Q_indexed)
else:
Q_loss = torch.mean(torch.sum(Q_val, 1))
self.actor.zero_grad()
Q_loss.backward()
from copy import deepcopy
delta_a = deepcopy(action_params.grad.data)
# step 2
action_params = self.actor_param(Variable(states))
delta_a[:] = self._invert_gradients(delta_a,
action_params,
grad_type="action_parameters",
inplace=True)
if self.zero_index_gradients:
delta_a[:] = self._zero_index_gradients(
delta_a, batch_action_indices=actions, inplace=True)
out = -torch.mul(delta_a, action_params)
self.actor_param.zero_grad()
out.backward(torch.ones(out.shape).to(self.device))
if self.clip_grad > 0:
torch.nn.utils.clip_grad_norm_(self.actor_param.parameters(),
self.clip_grad)
self.actor_param_optimiser.step()
soft_update_target_network(self.actor, self.actor_target,
self.tau_actor)
soft_update_target_network(self.actor_param, self.actor_param_target,
self.tau_actor_param)
def save_models(self, prefix):
"""
saves the target actor and critic models
:param prefix: the count of episodes iterated
:return:
"""
torch.save(self.actor.state_dict(), prefix + '_actor.pt')
torch.save(self.actor_param.state_dict(), prefix + '_actor_param.pt')
print('Models saved successfully')
def load_models(self, prefix):
"""
loads the target actor and critic models, and copies them onto actor and critic models
:param prefix: the count of episodes iterated (used to find the file name)
:param target: whether to load the target newtwork too (not necessary for evaluation)
:return:
"""
# also try load on CPU if no GPU available?
self.actor.load_state_dict(
torch.load(prefix + '_actor.pt', map_location='cpu'))
self.actor_param.load_state_dict(
torch.load(prefix + '_actor_param.pt', map_location='cpu'))
print('Models loaded successfully')
