def expand(self, next_layer, count=1):
"""
Expand the node by querying the oracle model for every possible action
:param next_layer: list of nodes at the next depth, to be updated with new children nodes
:param count: number of times each transition must be evaluated
"""
if self.state is None:
raise Exception("The state should be set before expanding a node")
try:
actions = self.state.get_available_actions()
except AttributeError:
actions = range(1, self.state.action_space.n)
self.planner.openings += count
if self.done and PlaTyPOOSNode.STOP_ON_ANY_TERMINAL_STATE:
return
for _ in range(count):
for action in actions:
state = safe_deepcopy_env(self.state)
_, reward, done, _ = state.step(action)
if action not in self.children:
self.children[action] = type(self)(self,
self.planner,
state,
depth=self.depth + 1)
next_layer.append(self.children[action])
self.children[action].update(reward, done)
def plan(self, state, observation):
for i in range(self.config['iterations']):
if (i + 1) % 10 == 0:
logger.debug('{} / {}'.format(i + 1,
self.config['iterations']))
self.run(safe_deepcopy_env(state), observation)
return self.get_plan()
def plan(self, observation):
action_distribution = Normal(
torch.zeros(self.config["horizon"], self.action_size),
torch.ones(self.config["horizon"], self.action_size))
for i in range(self.config["iterations"]):
# Evaluate J action sequences from the current belief (in batch)
actions = action_distribution.sample([self.config["candidates"]
]) # Sample actions
candidates = [
safe_deepcopy_env(self.env)
for _ in range(self.config["candidates"])
]
returns = torch.zeros(self.config["candidates"])
# Sample next states
for t in range(self.config["horizon"]):
for c, candidate in enumerate(candidates):
_, reward, _, _ = candidate.step(actions[c, t])
returns[c] += self.config["gamma"]**t * reward
# Re-fit belief to the K best action sequences
_, topk = returns.topk(self.config["top_candidates"],
largest=True,
sorted=False) # K ← argsort({R(j)}
best_actions = actions[topk]
# Update belief with new means and standard deviations
action_distribution = Normal(
best_actions.mean(dim=0),
best_actions.std(dim=0, unbiased=False))
# Return first action mean µ_t
return action_distribution.mean.tolist()
def plan(self, state, observation):
for self.episode in range(self.config['episodes']):
if (self.episode + 1) % max(self.config['episodes'] // 10, 1) == 0:
logger.debug('{} / {}'.format(self.episode + 1,
self.config['episodes']))
self.run(safe_deepcopy_env(state))
return self.get_plan()
def expand(self, state, leaves, update_children=False):
if state is None:
raise Exception("The state should be set before expanding a node")
try:
actions = state.get_available_actions()
except AttributeError:
actions = range(state.action_space.n)
for action in actions:
self.children[action] = type(self)(self, self.planner)
if update_children:
_, reward, done, _ = safe_deepcopy_env(state).step(action)
self.children[action].update(reward, done)
idx = leaves.index(self)
leaves = leaves[:idx] + list(self.children.values()) + leaves[idx + 1:]
return leaves
def expand(self, leaves):
if self.state is None:
raise Exception("The state should be set before expanding a node")
try:
actions = self.state.get_available_actions()
except AttributeError:
actions = range(self.state.action_space.n)
for action in actions:
self.children[action] = type(self)(self,
self.planner,
state=safe_deepcopy_env(
self.state),
depth=self.depth + 1)
_, reward, done, _ = self.children[action].state.step(action)
self.children[action].update(reward, done)
leaves.remove(self)
leaves.extend(self.children.values())
