def _action(self, time_step, policy_state, seed=None):
first_obs = tf.nest.flatten(time_step.observation)[0]
batch_size = tf.compat.dimension_value(
first_obs.shape[0]) or tf.shape(first_obs)[0]
policy_choice = self._mixture_distribution.sample(batch_size)
policy_steps = [
policy.action(time_step, policy_state) for policy in self._policies
]
policy_actions = nest_utils.stack_nested_tensors(
[step.action for step in policy_steps], axis=-1)
policy_infos = nest_utils.stack_nested_tensors(
[step.info for step in policy_steps], axis=-1)
expanded_choice = tf.expand_dims(policy_choice, axis=-1)
mixture_action = tf.nest.map_structure(
lambda t: tf.gather(t, policy_choice, batch_dims=1), policy_actions)
expanded_mixture_info = tf.nest.map_structure(
lambda t: tf.gather(t, expanded_choice, batch_dims=1, axis=-1),
policy_infos)
mixture_info = tf.nest.map_structure(lambda t: tf.squeeze(t, axis=-1),
expanded_mixture_info)
return policy_step.PolicyStep(mixture_action, policy_state, {
MIXTURE_AGENT_ID: policy_choice,
SUBPOLICY_INFO: mixture_info
})
def get_episode(
self,
batch_size: Optional[int] = None,
truncate_episode_at: Optional[int] = None
) -> Tuple[EnvStep, np.ndarray]:
if batch_size is None:
episode = self._get_episode(truncate_episode_at)
mask = np.ones((len(episode), ))
return nest_utils.stack_nested_tensors(episode), mask
if batch_size <= 0:
raise ValueError('Invalid batch size %s.' % batch_size)
episodes = []
episode_lengths = []
for _ in range(batch_size):
next_episode = self._get_episode(truncate_episode_at)
episodes.append(next_episode)
episode_lengths.append(len(next_episode))
max_length = max(episode_lengths)
for episode in episodes:
episode.extend([episode[-1]] * (max_length - len(episode)))
batched_episodes = nest_utils.stack_nested_tensors(
[nest_utils.stack_nested_tensors(episode) for episode in episodes])
valid_steps = (tf.range(max_length)[None, :] <
tf.convert_to_tensor(episode_lengths)[:, None])
return batched_episodes, valid_steps
def _action(self, time_step, policy_state, seed=None):
tf.debugging.assert_greater_equal(
self._mixture_distribution,
0.0,
message='Negative probability in mixture distribution.')
policy_sampler = tfd.Categorical(probs=self._mixture_distribution)
first_obs = tf.nest.flatten(time_step.observation)[0]
batch_size = tf.compat.dimension_value(
first_obs.shape[0]) or tf.shape(first_obs)[0]
policy_choice = policy_sampler.sample(batch_size)
policy_actions = nest_utils.stack_nested_tensors([
policy.action(time_step, policy_state).action
for policy in self._policies
],
axis=-1)
# TODO(b/147134243) Remove the expand_dims and squeeze once the fix in
# b/143205052 is live.
expanded_choice = tf.expand_dims(policy_choice, axis=-1)
expanded_mixture_action = tf.nest.map_structure(
lambda t: tf.gather(t, expanded_choice, batch_dims=1),
policy_actions)
mixture_action = tf.nest.map_structure(
lambda t: tf.squeeze(t, axis=-1), expanded_mixture_action)
return policy_step.PolicyStep(mixture_action, policy_state)
def sample(self, batch_size):
dummy_action_step = policy_step.PolicyStep(
action=tf.constant([tf.int32.min]))
dummy_time_step = ts.TimeStep(step_type=tf.constant([tf.int32.min]),
reward=(np.nan * tf.ones(1)),
discount=(np.nan * tf.ones(1)),
observation=None)
trajs = []
for transition in random.sample(self.buffer, batch_size):
traj1 = trajectory.from_transition(transition.time_step,
transition.action_step,
transition.next_time_step)
traj2 = trajectory.from_transition(transition.next_time_step,
dummy_action_step,
dummy_time_step)
trajs.append(
nest_utils.unbatch_nested_tensors(
nest_utils.stack_nested_tensors([traj1, traj2], axis=1)))
return nest_utils.stack_nested_tensors(trajs)
def testStackNestedTensors(self):
shape = [5, 8]
batch_size = 3
batched_shape = [batch_size,] + shape
specs = self.nest_spec(shape, include_sparse=False)
unstacked_tensors = [self.zeros_from_spec(specs) for _ in range(batch_size)]
stacked_tensor = nest_utils.stack_nested_tensors(unstacked_tensors)
tf.nest.assert_same_structure(specs, stacked_tensor)
assert_shapes = lambda tensor: self.assertEqual(tensor.shape, batched_shape)
tf.nest.map_structure(assert_shapes, stacked_tensor)
def testStackNestedTensorsAxis1(self):
shape = [5, 8]
stack_dim = 3
stacked_shape = [5, 3, 8]
specs = self.nest_spec(shape, include_sparse=False)
unstacked_tensors = [self.zeros_from_spec(specs)] * stack_dim
stacked_tensor = nest_utils.stack_nested_tensors(unstacked_tensors, axis=1)
tf.nest.assert_same_structure(specs, stacked_tensor)
assert_shapes = lambda tensor: self.assertEqual(tensor.shape, stacked_shape)
tf.nest.map_structure(assert_shapes, stacked_tensor)
def setUp(self):
super(BatchedPyMetricTest, self).setUp()
# Order of args for trajectory methods:
# observation, action, policy_info, reward, discount
ts0 = nest_utils.stack_nested_tensors([
trajectory.boundary((), (), (), 0., 1.),
trajectory.boundary((), (), (), 0., 1.)
])
ts1 = nest_utils.stack_nested_tensors([
trajectory.first((), (), (), 1., 1.),
trajectory.first((), (), (), 2., 1.)
])
ts2 = nest_utils.stack_nested_tensors([
trajectory.last((), (), (), 3., 1.),
trajectory.last((), (), (), 4., 1.)
])
ts3 = nest_utils.stack_nested_tensors([
trajectory.boundary((), (), (), 0., 1.),
trajectory.boundary((), (), (), 0., 1.)
])
ts4 = nest_utils.stack_nested_tensors([
trajectory.first((), (), (), 5., 1.),
trajectory.first((), (), (), 6., 1.)
])
ts5 = nest_utils.stack_nested_tensors([
trajectory.last((), (), (), 7., 1.),
trajectory.last((), (), (), 8., 1.)
])
self._ts = [ts0, ts1, ts2, ts3, ts4, ts5]
def _create_trajectories(self):
# Order of args for trajectory methods:
# observation, action, policy_info, reward, discount
ts0 = nest_utils.stack_nested_tensors([
trajectory.boundary((), (), (), 0., 1.),
trajectory.boundary((), (), (), 0., 1.)
])
ts1 = nest_utils.stack_nested_tensors([
trajectory.first((), (), (), 1., 1.),
trajectory.first((), (), (), 2., 1.)
])
ts2 = nest_utils.stack_nested_tensors([
trajectory.last((), (), (), 3., 1.),
trajectory.last((), (), (), 4., 1.)
])
ts3 = nest_utils.stack_nested_tensors([
trajectory.boundary((), (), (), 0., 1.),
trajectory.boundary((), (), (), 0., 1.)
])
ts4 = nest_utils.stack_nested_tensors([
trajectory.first((), (), (), 5., 1.),
trajectory.first((), (), (), 6., 1.)
])
ts5 = nest_utils.stack_nested_tensors([
trajectory.last((), (), (), 7., 1.),
trajectory.last((), (), (), 8., 1.)
])
return [ts0, ts1, ts2, ts3, ts4, ts5]
def day_preds(date_str,contract_str,c,model):
s = StockEnvBasic(date_str=date_str,contract_str=contract_str,**c.stock_env)
obs = []
times = range(c.stock_env['time_start_trade'],c.stock_env['time_end'])
the_ts = s.reset()
while not the_ts.is_last():
obs.append(the_ts.observation)
action = 1
the_ts = s.step(action)
obs = nest_utils.stack_nested_tensors(obs)
preds = model(obs,is_training=False)
return times,preds
def testNumActions(self, dtype):
if not dtype.is_integer:
self.skipTest('testNumActions only applies to integer dtypes')
batch_size = 1000
# Create action spec, time_step and spec with max_num_arms = 4.
action_spec = tensor_spec.BoundedTensorSpec((), dtype, 0, 3)
time_step_spec, time_step_1 = self.create_time_step(
use_per_arm_features=True, num_arms=2)
_, time_step_2 = self.create_time_step(use_per_arm_features=True,
num_arms=3)
# First half of time_step batch will have num_action = 2 and second
# half will have num_actions = 3.
half_batch_size = int(batch_size / 2)
time_step = nest_utils.stack_nested_tensors(
[time_step_1] * half_batch_size + [time_step_2] * half_batch_size)
# The features for the chosen arm is saved to policy_info.
chosen_arm_features_info = (
policy_utilities.create_chosen_arm_features_info_spec(
time_step_spec.observation))
info_spec = policy_utilities.PerArmPolicyInfo(
chosen_arm_features=chosen_arm_features_info)
policy = random_tf_policy.RandomTFPolicy(time_step_spec=time_step_spec,
action_spec=action_spec,
info_spec=info_spec,
accepts_per_arm_features=True,
emit_log_probability=True)
action_step = policy.action(time_step)
tf.nest.assert_same_structure(action_spec, action_step.action)
# Sample from the policy 1000 times, and ensure that actions considered
# invalid according to the mask are never chosen.
step = self.evaluate(action_step)
action_ = step.action
self.assertTrue(np.all(action_ >= 0))
self.assertTrue(np.all(action_[:half_batch_size] < 2))
self.assertTrue(np.all(action_[half_batch_size:] < 3))
# With num_action valid actions, probabilities should be 1/num_actions.
self.assertAllClose(
step.info.log_probability[:half_batch_size],
tf.constant(np.log(1. / 2), shape=[half_batch_size]))
self.assertAllClose(
step.info.log_probability[half_batch_size:],
tf.constant(np.log(1. / 3), shape=[half_batch_size]))
def get_step(self,
batch_size: Optional[int] = None,
num_steps: Optional[int] = None) -> EnvStep:
if batch_size is not None:
raise ValueError(
'This dataset does not support batched step sampling.')
if num_steps is None:
return self._get_step()
env_steps = []
for _ in range(num_steps):
next_step = self._get_step()
env_steps.append(next_step)
return nest_utils.stack_nested_tensors(env_steps)
def _resample_action_fn(self, resample_input):
ac_mean, scale, step_type, *flat_observation = resample_input # expects single ac, obs, step
n, k = self._n, self._k
# samples "best" safe action out of 50
# sampled_ac = actions.sample(n)
observation = tf.nest.pack_sequence_as(self.time_step_spec.observation,
flat_observation)
obs = nest_utils.stack_nested_tensors([observation for _ in range(n)])
actions = self._actor_network.output_spec.build_distribution(
loc=ac_mean, scale=scale)
sampled_ac = actions.sample(n)
ac_outer_rank = nest_utils.get_outer_rank(sampled_ac, self.action_spec)
ac_batch_squash = utils.BatchSquash(ac_outer_rank)
sampled_ac = tf.nest.map_structure(ac_batch_squash.flatten, sampled_ac)
obs_outer_rank = nest_utils.get_outer_rank(
obs, self.time_step_spec.observation)
obs_batch_squash = utils.BatchSquash(obs_outer_rank)
obs = tf.nest.map_structure(obs_batch_squash.flatten, obs)
q_val, _ = self._safety_critic_network((obs, sampled_ac), step_type)
fail_prob = tf.nn.sigmoid(q_val)
safe_ac_mask = fail_prob < self._safety_threshold
# pdb.set_trace()
[_, safe_ac_mask, sampled_ac, fail_prob] = tf.while_loop(
cond=resample_cond,
body=self._loop_body_fn(ac_batch_squash, obs, step_type, ac_mean),
loop_vars=[scale, safe_ac_mask, sampled_ac, fail_prob],
maximum_iterations=k)
sampled_ac = tf.nest.map_structure(ac_batch_squash.unflatten,
sampled_ac)
if self._resample_counter is not None:
logging.debug('resampled %d times',
self._resample_counter.result())
safe_ac_idx = tf.where(safe_ac_mask)
fail_prob_safe = tf.gather(fail_prob, safe_ac_idx[:, 0])
safe_idx = self._get_safe_idx(safe_ac_mask, fail_prob, sampled_ac,
safe_ac_idx, actions, fail_prob_safe)
ac = sampled_ac[safe_idx]
return ac
def _apply_actor_network(self, time_step, policy_state):
has_batch_dim = time_step.step_type.shape.as_list()[0] > 1
observation = time_step.observation
if self._observation_normalizer:
observation = self._observation_normalizer.normalize(observation)
actions, policy_state = self._actor_network(observation,
time_step.step_type,
policy_state)
if has_batch_dim:
return actions, policy_state
# samples "best" safe action out of 50
sampled_ac = actions.sample(50)
obs = nest_utils.stack_nested_tensors(
[time_step.observation for _ in range(50)])
q_val, _ = self._safety_critic_network((obs, sampled_ac),
time_step.step_type)
fail_prob = tf.nn.sigmoid(q_val)
safe_ac_mask = fail_prob < self._safety_threshold
safe_ac_idx = tf.where(safe_ac_mask)
resample_count = 0
while resample_count < 4 and not safe_ac_idx.shape.as_list()[0]:
if self._resample_metric is not None:
self._resample_metric()
resample_count += 1
scale = actions.scale * 1.5 # increase variance by constant 1.5
actions = self._actor_network.output_spec.build_distribution(
loc=actions.loc, scale=scale)
sampled_ac = actions.sample(50)
q_val, _ = self._safety_critic_network((obs, sampled_ac),
time_step.step_type)
fail_prob = tf.nn.sigmoid(q_val)
safe_ac_idx = tf.where(
tf.squeeze(fail_prob) < self._safety_threshold)
if not safe_ac_idx.shape.as_list()[0]: # return safest action
safe_ac_idx = tf.math.argmin(fail_prob)
return sampled_ac[safe_ac_idx], policy_state
actions = tf.squeeze(tf.gather(sampled_ac, safe_ac_idx))
fail_prob_safe = tf.gather(fail_prob, safe_ac_idx)
safe_idx = tf.math.argmax(fail_prob_safe)
return actions[safe_idx], policy_state
def create_batch(self, single_time_step, batch_size):
batch_time_step = nest_utils.stack_nested_tensors(
[single_time_step] * batch_size)
return batch_time_step
def _apply_actor_network(self, time_step, policy_state):
has_batch_dim = time_step.step_type.shape.as_list()[0] > 1
observation = time_step.observation
if self._observation_normalizer:
observation = self._observation_normalizer.normalize(observation)
actions, policy_state = self._actor_network(observation,
time_step.step_type,
policy_state,
training=self._training)
if has_batch_dim:
return actions, policy_state
# samples "best" safe action out of 50
sampled_ac = actions.sample(50)
obs = nest_utils.stack_nested_tensors(
[time_step.observation for _ in range(50)])
obs_outer_rank = nest_utils.get_outer_rank(
obs, self.time_step_spec.observation)
ac_outer_rank = nest_utils.get_outer_rank(sampled_ac, self.action_spec)
obs_batch_squash = utils.BatchSquash(obs_outer_rank)
ac_batch_squash = utils.BatchSquash(ac_outer_rank)
obs = tf.nest.map_structure(obs_batch_squash.flatten, obs)
sampled_ac = tf.nest.map_structure(ac_batch_squash.flatten, sampled_ac)
q_val, _ = self._safety_critic_network((obs, sampled_ac),
time_step.step_type)
fail_prob = tf.nn.sigmoid(q_val)
safe_ac_mask = fail_prob < self._safety_threshold
safe_ac_idx = tf.where(safe_ac_mask)
resample_count = 0
start_time = time.time()
while self._training and resample_count < 4 and not safe_ac_idx.shape.as_list(
)[0]:
if self._resample_counter is not None:
self._resample_counter()
resample_count += 1
if isinstance(actions, dist_utils.SquashToSpecNormal):
scale = actions.input_distribution.scale * 1.5 # increase variance by constant 1.5
ac_mean = actions.mean()
else:
scale = actions.scale * 1.5
ac_mean = actions.mean()
actions = self._actor_network.output_spec.build_distribution(
loc=ac_mean, scale=scale)
sampled_ac = actions.sample(50)
sampled_ac = tf.nest.map_structure(ac_batch_squash.flatten,
sampled_ac)
q_val, _ = self._safety_critic_network((obs, sampled_ac),
time_step.step_type)
fail_prob = tf.nn.sigmoid(q_val)
safe_ac_idx = tf.where(fail_prob < self._safety_threshold)
# logging.debug('resampled {} times, {} seconds'.format(resample_count, time.time() - start_time))
sampled_ac = ac_batch_squash.unflatten(sampled_ac)
if None in safe_ac_idx.shape.as_list() or not np.prod(
safe_ac_idx.shape.as_list()): # return safest action
safe_idx = tf.argmin(fail_prob)
else:
sampled_ac = tf.gather(sampled_ac, safe_ac_idx)
fail_prob_safe = tf.gather(fail_prob, safe_ac_idx)
if self._training:
safe_idx = tf.argmax(fail_prob_safe)[
0] # picks most unsafe action out of "safe" options
else:
safe_idx = tf.argmin(fail_prob_safe)[0]
ac = sampled_ac[safe_idx]
assert ac.shape.as_list(
)[0] == 1, 'action shape is not correct: {}'.format(ac.shape.as_list())
return ac, policy_state