def create_encoder(
self, state_in: tf.Tensor, action_in: tf.Tensor, done_in: tf.Tensor, reuse: bool
) -> Tuple[tf.Tensor, tf.Tensor, tf.Tensor]:
"""
Creates the encoder for the discriminator
:param state_in: The encoded observation input
:param action_in: The action input
:param done_in: The done flags input
:param reuse: If true, the weights will be shared with the previous encoder created
"""
with tf.variable_scope("GAIL_model"):
if self.use_actions:
concat_input = tf.concat([state_in, action_in, done_in], axis=1)
else:
concat_input = state_in
hidden_1 = tf.layers.dense(
concat_input,
self.h_size,
activation=LearningModel.swish,
name="gail_d_hidden_1",
reuse=reuse,
)
hidden_2 = tf.layers.dense(
hidden_1,
self.h_size,
activation=LearningModel.swish,
name="gail_d_hidden_2",
reuse=reuse,
)
z_mean = None
if self.use_vail:
# Latent representation
z_mean = tf.layers.dense(
hidden_2,
self.z_size,
reuse=reuse,
name="gail_z_mean",
kernel_initializer=LearningModel.scaled_init(0.01),
)
self.noise = tf.random_normal(tf.shape(z_mean), dtype=tf.float32)
# Sampled latent code
self.z = z_mean + self.z_sigma * self.noise * self.use_noise
estimate_input = self.z
else:
estimate_input = hidden_2
estimate = tf.layers.dense(
estimate_input,
1,
activation=tf.nn.sigmoid,
name="gail_d_estimate",
reuse=reuse,
)
return estimate, z_mean, concat_input
def create_cc_actor(self, hidden_policy, scope):
"""
Creates Continuous control actor for SAC.
:param hidden_policy: Output of feature extractor (i.e. the input for vector obs, output of CNN for visual obs).
:param num_layers: TF scope to assign whatever is created in this block.
"""
# Create action input (continuous)
self.action_holder = tf.placeholder(shape=[None, self.act_size[0]],
dtype=tf.float32,
name="action_holder")
self.external_action_in = self.action_holder
scope = self.join_scopes(scope, "policy")
with tf.variable_scope(scope):
hidden_policy = self.create_vector_observation_encoder(
hidden_policy,
self.h_size,
self.activ_fn,
self.num_layers,
"encoder",
False,
)
if self.use_recurrent:
hidden_policy, memory_out = self.create_recurrent_encoder(
hidden_policy,
self.policy_memory_in,
self.sequence_length,
name="lstm_policy",
)
self.policy_memory_out = memory_out
with tf.variable_scope(scope):
mu = tf.layers.dense(
hidden_policy,
self.act_size[0],
activation=None,
name="mu",
kernel_initializer=LearningModel.scaled_init(0.01),
)
# Policy-dependent log_sigma_sq
log_sigma_sq = tf.layers.dense(
hidden_policy,
self.act_size[0],
activation=None,
name="log_std",
kernel_initializer=LearningModel.scaled_init(0.01),
)
self.log_sigma_sq = tf.clip_by_value(log_sigma_sq, LOG_STD_MIN,
LOG_STD_MAX)
sigma_sq = tf.exp(self.log_sigma_sq)
# Do the reparameterization trick
policy_ = mu + tf.random_normal(tf.shape(mu)) * sigma_sq
_gauss_pre = -0.5 * (((policy_ - mu) /
(tf.exp(self.log_sigma_sq) + EPSILON))**2 +
2 * self.log_sigma_sq + np.log(2 * np.pi))
all_probs = tf.reduce_sum(_gauss_pre, axis=1, keepdims=True)
self.entropy = tf.reduce_sum(self.log_sigma_sq +
0.5 * np.log(2.0 * np.pi * np.e),
axis=-1)
# Squash probabilities
# Keep deterministic around in case we want to use it.
self.deterministic_output = tf.tanh(mu)
# Note that this is just for symmetry with PPO.
self.output_pre = tf.tanh(policy_)
# Squash correction
all_probs -= tf.reduce_sum(tf.log(1 - self.output_pre**2 +
EPSILON),
axis=1,
keepdims=True)
self.all_log_probs = all_probs
self.selected_actions = tf.stop_gradient(self.output_pre)
self.action_probs = all_probs
# Extract output for Barracuda
self.output = tf.identity(self.output_pre, name="action")
# Get all policy vars
self.policy_vars = self.get_vars(scope)
def create_cc_actor_critic(self, h_size: int, num_layers: int,
vis_encode_type: EncoderType) -> None:
"""
Creates Continuous control actor-critic model.
:param h_size: Size of hidden linear layers.
:param num_layers: Number of hidden linear layers.
"""
hidden_streams = self.create_observation_streams(
2, h_size, num_layers, vis_encode_type)
if self.use_recurrent:
self.memory_in = tf.placeholder(shape=[None, self.m_size],
dtype=tf.float32,
name="recurrent_in")
_half_point = int(self.m_size / 2)
hidden_policy, memory_policy_out = self.create_recurrent_encoder(
hidden_streams[0],
self.memory_in[:, :_half_point],
self.sequence_length,
name="lstm_policy",
)
hidden_value, memory_value_out = self.create_recurrent_encoder(
hidden_streams[1],
self.memory_in[:, _half_point:],
self.sequence_length,
name="lstm_value",
)
self.memory_out = tf.concat([memory_policy_out, memory_value_out],
axis=1,
name="recurrent_out")
else:
hidden_policy = hidden_streams[0]
hidden_value = hidden_streams[1]
mu = tf.layers.dense(
hidden_policy,
self.act_size[0],
activation=None,
kernel_initializer=LearningModel.scaled_init(0.01),
reuse=tf.AUTO_REUSE,
)
self.log_sigma_sq = tf.get_variable(
"log_sigma_squared",
[self.act_size[0]],
dtype=tf.float32,
initializer=tf.zeros_initializer(),
)
sigma_sq = tf.exp(self.log_sigma_sq)
self.epsilon = tf.placeholder(shape=[None, self.act_size[0]],
dtype=tf.float32,
name="epsilon")
# Clip and scale output to ensure actions are always within [-1, 1] range.
self.output_pre = mu + tf.sqrt(sigma_sq) * self.epsilon
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(output_post)
# Compute probability of model output.
all_probs = (-0.5 * tf.square(tf.stop_gradient(self.output_pre) - mu) /
sigma_sq - 0.5 * tf.log(2.0 * np.pi) -
0.5 * self.log_sigma_sq)
self.all_log_probs = tf.identity(all_probs, name="action_probs")
self.entropy = 0.5 * tf.reduce_mean(
tf.log(2 * np.pi * np.e) + self.log_sigma_sq)
self.create_value_heads(self.stream_names, hidden_value)
self.all_old_log_probs = tf.placeholder(shape=[None, self.act_size[0]],
dtype=tf.float32,
name="old_probabilities")
# We keep these tensors the same name, but use new nodes to keep code parallelism with discrete control.
self.log_probs = tf.reduce_sum((tf.identity(self.all_log_probs)),
axis=1,
keepdims=True)
self.old_log_probs = tf.reduce_sum(
(tf.identity(self.all_old_log_probs)), axis=1, keepdims=True)
def create_dc_actor_critic(self, h_size: int, num_layers: int,
vis_encode_type: EncoderType) -> None:
"""
Creates Discrete control actor-critic model.
:param h_size: Size of hidden linear layers.
:param num_layers: Number of hidden linear layers.
"""
hidden_streams = self.create_observation_streams(
1, h_size, num_layers, vis_encode_type)
hidden = hidden_streams[0]
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 = tf.concat([hidden, prev_action_oh], axis=1)
self.memory_in = tf.placeholder(shape=[None, self.m_size],
dtype=tf.float32,
name="recurrent_in")
hidden, memory_out = self.create_recurrent_encoder(
hidden, self.memory_in, self.sequence_length)
self.memory_out = tf.identity(memory_out, name="recurrent_out")
policy_branches = []
for size in self.act_size:
policy_branches.append(
tf.layers.dense(
hidden,
size,
activation=None,
use_bias=False,
kernel_initializer=LearningModel.scaled_init(0.01),
))
self.all_log_probs = tf.concat(policy_branches,
axis=1,
name="action_probs")
self.action_masks = tf.placeholder(shape=[None,
sum(self.act_size)],
dtype=tf.float32,
name="action_masks")
output, _, normalized_logits = self.create_discrete_action_masking_layer(
self.all_log_probs, self.action_masks, self.act_size)
self.output = tf.identity(output)
self.normalized_logits = tf.identity(normalized_logits, name="action")
self.create_value_heads(self.stream_names, hidden)
self.action_holder = tf.placeholder(shape=[None,
len(policy_branches)],
dtype=tf.int32,
name="action_holder")
self.action_oh = tf.concat(
[
tf.one_hot(self.action_holder[:, i], self.act_size[i])
for i in range(len(self.act_size))
],
axis=1,
)
self.selected_actions = tf.stop_gradient(self.action_oh)
self.all_old_log_probs = tf.placeholder(
shape=[None, sum(self.act_size)],
dtype=tf.float32,
name="old_probabilities")
_, _, old_normalized_logits = self.create_discrete_action_masking_layer(
self.all_old_log_probs, self.action_masks, self.act_size)
action_idx = [0] + list(np.cumsum(self.act_size))
self.entropy = tf.reduce_sum(
(tf.stack(
[
tf.nn.softmax_cross_entropy_with_logits_v2(
labels=tf.nn.softmax(
self.all_log_probs[:,
action_idx[i]:action_idx[i +
1]]),
logits=self.all_log_probs[:,
action_idx[i]:action_idx[i +
1]],
) for i in range(len(self.act_size))
],
axis=1,
)),
axis=1,
)
self.log_probs = tf.reduce_sum(
(tf.stack(
[
-tf.nn.softmax_cross_entropy_with_logits_v2(
labels=self.action_oh[:,
action_idx[i]:action_idx[i + 1]],
logits=normalized_logits[:,
action_idx[i]:action_idx[i +
1]],
) for i in range(len(self.act_size))
],
axis=1,
)),
axis=1,
keepdims=True,
)
self.old_log_probs = tf.reduce_sum(
(tf.stack(
[
-tf.nn.softmax_cross_entropy_with_logits_v2(
labels=self.action_oh[:,
action_idx[i]:action_idx[i + 1]],
logits=old_normalized_logits[:, action_idx[i]:
action_idx[i + 1]],
) for i in range(len(self.act_size))
],
axis=1,
)),
axis=1,
keepdims=True,
)