def create_sac_value_head(self, stream_names, hidden_input, num_layers,
h_size, scope):
"""
Creates one value estimator head for each reward signal in stream_names.
Also creates the node corresponding to the mean of all the value heads in self.value.
self.value_head is a dictionary of stream name to node containing the value estimator head for that signal.
:param stream_names: The list of reward signal names
:param hidden_input: The last layer of the Critic. The heads will consist of one dense hidden layer on top
of the hidden input.
:param num_layers: Number of hidden layers for value network
:param h_size: size of hidden layers for value network
:param scope: TF scope for value network.
"""
with tf.variable_scope(scope):
value_hidden = ModelUtils.create_vector_observation_encoder(
hidden_input, h_size, self.activ_fn, num_layers, "encoder",
False)
if self.use_recurrent:
value_hidden, memory_out = ModelUtils.create_recurrent_encoder(
value_hidden,
self.value_memory_in,
self.sequence_length_ph,
name="lstm_value",
)
self.value_memory_out = memory_out
self.create_value_heads(stream_names, value_hidden)
def _create_cc_actor(
self,
encoded: tf.Tensor,
tanh_squash: bool = False,
reparameterize: bool = False,
condition_sigma_on_obs: bool = True,
) -> None:
"""
Creates Continuous control actor-critic model.
:param h_size: Size of hidden linear layers.
:param num_layers: Number of hidden linear layers.
:param vis_encode_type: Type of visual encoder to use if visual input.
:param tanh_squash: Whether to use a tanh function, or a clipped output.
:param reparameterize: Whether we are using the resampling trick to update the policy.
"""
if self.use_recurrent:
self.memory_in = tf.placeholder(shape=[None, self.m_size],
dtype=tf.float32,
name="recurrent_in")
hidden_policy, memory_policy_out = ModelUtils.create_recurrent_encoder(
encoded,
self.memory_in,
self.sequence_length_ph,
name="lstm_policy")
self.memory_out = tf.identity(memory_policy_out,
name="recurrent_out")
else:
hidden_policy = encoded
with tf.variable_scope("policy"):
distribution = GaussianDistribution(
hidden_policy,
self.act_size,
reparameterize=reparameterize,
tanh_squash=tanh_squash,
condition_sigma=condition_sigma_on_obs,
)
if tanh_squash:
self.output_pre = distribution.sample
self.output = tf.identity(self.output_pre, name="action")
else:
self.output_pre = distribution.sample
# Clip and scale output to ensure actions are always within [-1, 1] range.
output_post = tf.clip_by_value(self.output_pre, -3, 3) / 3
self.output = tf.identity(output_post, name="action")
self.selected_actions = tf.stop_gradient(self.output)
self.all_log_probs = tf.identity(distribution.log_probs,
name="action_probs")
self.entropy = distribution.entropy
# We keep these tensors the same name, but use new nodes to keep code parallelism with discrete control.
self.total_log_probs = distribution.total_log_probs
def _create_dc_actor(self, encoded: tf.Tensor) -> None:
"""
Creates Discrete control actor-critic model.
:param h_size: Size of hidden linear layers.
:param num_layers: Number of hidden linear layers.
:param vis_encode_type: Type of visual encoder to use if visual input.
"""
if self.use_recurrent:
self.prev_action = tf.placeholder(shape=[None,
len(self.act_size)],
dtype=tf.int32,
name="prev_action")
prev_action_oh = tf.concat(
[
tf.one_hot(self.prev_action[:, i], self.act_size[i])
for i in range(len(self.act_size))
],
axis=1,
)
hidden_policy = tf.concat([encoded, prev_action_oh], axis=1)
self.memory_in = tf.placeholder(shape=[None, self.m_size],
dtype=tf.float32,
name="recurrent_in")
hidden_policy, memory_policy_out = ModelUtils.create_recurrent_encoder(
hidden_policy,
self.memory_in,
self.sequence_length_ph,
name="lstm_policy",
)
self.memory_out = tf.identity(memory_policy_out, "recurrent_out")
else:
hidden_policy = encoded
self.action_masks = tf.placeholder(shape=[None,
sum(self.act_size)],
dtype=tf.float32,
name="action_masks")
with tf.variable_scope("policy"):
distribution = MultiCategoricalDistribution(
hidden_policy, self.act_size, self.action_masks)
# It's important that we are able to feed_dict a value into this tensor to get the
# right one-hot encoding, so we can't do identity on it.
self.output = distribution.sample
self.all_log_probs = tf.identity(distribution.log_probs, name="action")
self.selected_actions = tf.stop_gradient(
distribution.sample_onehot) # In discrete, these are onehot
self.entropy = distribution.entropy
self.total_log_probs = distribution.total_log_probs
def _create_cc_critic(
self, h_size: int, num_layers: int, vis_encode_type: EncoderType
) -> None:
"""
Creates Continuous control critic (value) network.
:param h_size: Size of hidden linear layers.
:param num_layers: Number of hidden linear layers.
:param vis_encode_type: The type of visual encoder to use.
"""
hidden_stream = ModelUtils.create_observation_streams(
self.policy.visual_in,
self.policy.processed_vector_in,
1,
h_size,
num_layers,
vis_encode_type,
)[0]
if self.policy.use_recurrent:
hidden_value, memory_value_out = ModelUtils.create_recurrent_encoder(
hidden_stream,
self.memory_in,
self.policy.sequence_length_ph,
name="lstm_value",
)
self.memory_out = memory_value_out
else:
hidden_value = hidden_stream
self.value_heads, self.value = ModelUtils.create_value_heads(
self.stream_names, hidden_value
)
self.all_old_log_probs = tf.placeholder(
shape=[None, sum(self.policy.act_size)],
dtype=tf.float32,
name="old_probabilities",
)
self.old_log_probs = tf.reduce_sum(
(tf.identity(self.all_old_log_probs)), axis=1, keepdims=True
)
def _create_dc_critic(self, h_size: int, num_layers: int,
vis_encode_type: EncoderType) -> None:
"""
Creates Discrete control critic (value) network.
:param h_size: Size of hidden linear layers.
:param num_layers: Number of hidden linear layers.
:param vis_encode_type: The type of visual encoder to use.
"""
hidden_stream = ModelUtils.create_observation_streams(
self.policy.visual_in,
self.policy.processed_vector_in,
1,
h_size,
num_layers,
vis_encode_type,
)[0]
if self.policy.use_recurrent:
hidden_value, memory_value_out = ModelUtils.create_recurrent_encoder(
hidden_stream,
self.memory_in,
self.policy.sequence_length_ph,
name="lstm_value",
)
self.memory_out = memory_value_out
else:
hidden_value = hidden_stream
self.value_heads, self.value = ModelUtils.create_value_heads(
self.stream_names, hidden_value)
self.all_old_log_probs = tf.placeholder(
shape=[None, sum(self.policy.act_size)],
dtype=tf.float32,
name="old_probabilities",
)
# Break old log log_probs into separate branches
old_log_prob_branches = ModelUtils.break_into_branches(
self.all_old_log_probs, self.policy.act_size)
_, _, old_normalized_logits = ModelUtils.create_discrete_action_masking_layer(
old_log_prob_branches, self.policy.action_masks,
self.policy.act_size)
action_idx = [0] + list(np.cumsum(self.policy.act_size))
self.old_log_probs = tf.reduce_sum(
(tf.stack(
[
-tf.nn.softmax_cross_entropy_with_logits_v2(
labels=self.policy.
selected_actions[:, action_idx[i]:action_idx[i + 1]],
logits=old_normalized_logits[:, action_idx[i]:
action_idx[i + 1]],
) for i in range(len(self.policy.act_size))
],
axis=1,
)),
axis=1,
keepdims=True,
)
def create_q_heads(
self,
stream_names,
hidden_input,
num_layers,
h_size,
scope,
reuse=False,
num_outputs=1,
):
"""
Creates two q heads for each reward signal in stream_names.
Also creates the node corresponding to the mean of all the value heads in self.value.
self.value_head is a dictionary of stream name to node containing the value estimator head for that signal.
:param stream_names: The list of reward signal names
:param hidden_input: The last layer of the Critic. The heads will consist of one dense hidden layer on top
of the hidden input.
:param num_layers: Number of hidden layers for Q network
:param h_size: size of hidden layers for Q network
:param scope: TF scope for Q network.
:param reuse: Whether or not to reuse variables. Useful for creating Q of policy.
:param num_outputs: Number of outputs of each Q function. If discrete, equal to number of actions.
"""
with tf.variable_scope(self.join_scopes(scope, "q1_encoding"),
reuse=reuse):
q1_hidden = ModelUtils.create_vector_observation_encoder(
hidden_input, h_size, self.activ_fn, num_layers, "q1_encoder",
reuse)
if self.use_recurrent:
q1_hidden, memory_out = ModelUtils.create_recurrent_encoder(
q1_hidden,
self.q1_memory_in,
self.sequence_length_ph,
name="lstm_q1",
)
self.q1_memory_out = memory_out
q1_heads = {}
for name in stream_names:
_q1 = tf.layers.dense(q1_hidden,
num_outputs,
name=f"{name}_q1")
q1_heads[name] = _q1
q1 = tf.reduce_mean(list(q1_heads.values()), axis=0)
with tf.variable_scope(self.join_scopes(scope, "q2_encoding"),
reuse=reuse):
q2_hidden = ModelUtils.create_vector_observation_encoder(
hidden_input, h_size, self.activ_fn, num_layers, "q2_encoder",
reuse)
if self.use_recurrent:
q2_hidden, memory_out = ModelUtils.create_recurrent_encoder(
q2_hidden,
self.q2_memory_in,
self.sequence_length_ph,
name="lstm_q2",
)
self.q2_memory_out = memory_out
q2_heads = {}
for name in stream_names:
_q2 = tf.layers.dense(q2_hidden,
num_outputs,
name=f"{name}_q2")
q2_heads[name] = _q2
q2 = tf.reduce_mean(list(q2_heads.values()), axis=0)
return q1_heads, q2_heads, q1, q2