def valor(env_fn, actor_critic=ActorCritic, ac_kwargs=dict(), disc=Discriminator, dc_kwargs=dict(), seed=0, episodes_per_epoch=40,
epochs=50, gamma=0.99, pi_lr=3e-4, vf_lr=1e-3, dc_lr=5e-4, train_v_iters=80, train_dc_iters=10, train_dc_interv=10,
lam=0.97, max_ep_len=1000, logger_kwargs=dict(), con_dim=5, save_freq=10, k=1):
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
seed += 10000 * proc_id()
torch.manual_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
ac_kwargs['action_space'] = env.action_space
# Model
actor_critic = actor_critic(input_dim=obs_dim[0]+con_dim, **ac_kwargs)
disc = disc(input_dim=obs_dim[0], context_dim=con_dim, **dc_kwargs)
# Buffer
local_episodes_per_epoch = int(episodes_per_epoch / num_procs())
buffer = Buffer(con_dim, obs_dim[0], act_dim[0], local_episodes_per_epoch, max_ep_len, train_dc_interv)
# Count variables
var_counts = tuple(count_vars(module) for module in
[actor_critic.policy, actor_critic.value_f, disc.policy])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d, \t d: %d\n'%var_counts)
# Optimizers
train_pi = torch.optim.Adam(actor_critic.policy.parameters(), lr=pi_lr)
train_v = torch.optim.Adam(actor_critic.value_f.parameters(), lr=vf_lr)
train_dc = torch.optim.Adam(disc.policy.parameters(), lr=dc_lr)
# Parameters Sync
sync_all_params(actor_critic.parameters())
sync_all_params(disc.parameters())
def update(e):
obs, act, adv, pos, ret, logp_old = [torch.Tensor(x) for x in buffer.retrieve_all()]
# Policy
_, logp, _ = actor_critic.policy(obs, act)
entropy = (-logp).mean()
# Policy loss
pi_loss = -(logp*(k*adv+pos)).mean()
# Train policy
train_pi.zero_grad()
pi_loss.backward()
average_gradients(train_pi.param_groups)
train_pi.step()
# Value function
v = actor_critic.value_f(obs)
v_l_old = F.mse_loss(v, ret)
for _ in range(train_v_iters):
v = actor_critic.value_f(obs)
v_loss = F.mse_loss(v, ret)
# Value function train
train_v.zero_grad()
v_loss.backward()
average_gradients(train_v.param_groups)
train_v.step()
# Discriminator
if (e+1) % train_dc_interv == 0:
print('Discriminator Update!')
con, s_diff = [torch.Tensor(x) for x in buffer.retrieve_dc_buff()]
_, logp_dc, _ = disc(s_diff, con)
d_l_old = -logp_dc.mean()
# Discriminator train
for _ in range(train_dc_iters):
_, logp_dc, _ = disc(s_diff, con)
d_loss = -logp_dc.mean()
train_dc.zero_grad()
d_loss.backward()
average_gradients(train_dc.param_groups)
train_dc.step()
_, logp_dc, _ = disc(s_diff, con)
dc_l_new = -logp_dc.mean()
else:
d_l_old = 0
dc_l_new = 0
# Log the changes
_, logp, _, v = actor_critic(obs, act)
pi_l_new = -(logp*(k*adv+pos)).mean()
v_l_new = F.mse_loss(v, ret)
kl = (logp_old - logp).mean()
logger.store(LossPi=pi_loss, LossV=v_l_old, KL=kl, Entropy=entropy, DeltaLossPi=(pi_l_new-pi_loss),
DeltaLossV=(v_l_new-v_l_old), LossDC=d_l_old, DeltaLossDC=(dc_l_new-d_l_old))
# logger.store(Adv=adv.reshape(-1).numpy().tolist(), Pos=pos.reshape(-1).numpy().tolist())
start_time = time.time()
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
context_dist = Categorical(logits=torch.Tensor(np.ones(con_dim)))
total_t = 0
for epoch in range(epochs):
actor_critic.eval()
disc.eval()
for _ in range(local_episodes_per_epoch):
c = context_dist.sample()
c_onehot = F.one_hot(c, con_dim).squeeze().float()
for _ in range(max_ep_len):
concat_obs = torch.cat([torch.Tensor(o.reshape(1, -1)), c_onehot.reshape(1, -1)], 1)
a, _, logp_t, v_t = actor_critic(concat_obs)
buffer.store(c, concat_obs.squeeze().detach().numpy(), a.detach().numpy(), r, v_t.item(), logp_t.detach().numpy())
logger.store(VVals=v_t)
o, r, d, _ = env.step(a.detach().numpy()[0])
ep_ret += r
ep_len += 1
total_t += 1
terminal = d or (ep_len == max_ep_len)
if terminal:
dc_diff = torch.Tensor(buffer.calc_diff()).unsqueeze(0)
con = torch.Tensor([float(c)]).unsqueeze(0)
_, _, log_p = disc(dc_diff, con)
buffer.end_episode(log_p.detach().numpy())
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, r, d, ep_ret, ep_len = env.reset(), 0, False, 0, 0
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, [actor_critic, disc], None)
# Update
actor_critic.train()
disc.train()
update(epoch)
# Log
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', total_t)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('LossDC', average_only=True)
logger.log_tabular('DeltaLossDC', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('Time', time.time()-start_time)
logger.dump_tabular()
def logger_setup(self, logger_kwargs, **kwargs):
self.logger = EpochLogger(**logger_kwargs)
for key, value in kwargs.items():
if key != 'env' and key != 'output_dir':
self.logger.log_tabular(key, value)
def ddpg(trajectory_output_path, env_fn, actor_critic=core.MLPActorCritic, ac_kwargs=dict(), seed=0,
steps_per_epoch=4000, epochs=100, replay_size=int(1e6), gamma=0.99,
polyak=0.995, pi_lr=1e-3, q_lr=1e-3, batch_size=100, start_steps=10000,
update_after=1000, update_every=50, act_noise=0.1, num_test_episodes=10,
max_ep_len=1000, logger_kwargs=dict(), save_freq=1):
"""
Deep Deterministic Policy Gradient (DDPG)
trajectory_output_path: The path to output the trajectory results
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: The constructor method for a PyTorch Module with an ``act``
method, a ``pi`` module, and a ``q`` module. The ``act`` method and
``pi`` module should accept batches of observations as inputs,
and ``q`` should accept a batch of observations and a batch of
actions as inputs. When called, these should return:
=========== ================ ======================================
Call Output Shape Description
=========== ================ ======================================
``act`` (batch, act_dim) | Numpy array of actions for each
| observation.
``pi`` (batch, act_dim) | Tensor containing actions from policy
| given observations.
``q`` (batch,) | Tensor containing the current estimate
| of Q* for the provided observations
| and actions. (Critical: make sure to
| flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the ActorCritic object
you provided to DDPG.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs to run and train agent.
replay_size (int): Maximum length of replay buffer.
gamma (float): Discount factor. (Always between 0 and 1.)
polyak (float): Interpolation factor in polyak averaging for target
networks. Target networks are updated towards main networks
according to:
.. math:: \\theta_{\\text{targ}} \\leftarrow
\\rho \\theta_{\\text{targ}} + (1-\\rho) \\theta
where :math:`\\rho` is polyak. (Always between 0 and 1, usually
close to 1.)
pi_lr (float): Learning rate for policy.
q_lr (float): Learning rate for Q-networks.
batch_size (int): Minibatch size for SGD.
start_steps (int): Number of steps for uniform-random action selection,
before running real policy. Helps exploration.
update_after (int): Number of env interactions to collect before
starting to do gradient descent updates. Ensures replay buffer
is full enough for useful updates.
update_every (int): Number of env interactions that should elapse
between gradient descent updates. Note: Regardless of how long
you wait between updates, the ratio of env steps to gradient steps
is locked to 1.
act_noise (float): Stddev for Gaussian exploration noise added to
policy at training time. (At test time, no noise is added.)
num_test_episodes (int): Number of episodes to test the deterministic
policy at the end of each epoch.
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
torch.manual_seed(seed)
np.random.seed(seed)
env, test_env = env_fn(), env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape[0]
# Action limit for clamping: critically, assumes all dimensions share the same bound!
act_limit = env.action_space.high[0]
# Create actor-critic module and target networks
ac = actor_critic(env.observation_space, env.action_space, **ac_kwargs)
ac_targ = deepcopy(ac)
# Freeze target networks with respect to optimizers (only update via polyak averaging)
for p in ac_targ.parameters():
p.requires_grad = False
# Experience buffer
replay_buffer = ReplayBuffer(obs_dim=obs_dim, act_dim=act_dim, size=replay_size)
# Count variables (protip: try to get a feel for how different size networks behave!)
var_counts = tuple(core.count_vars(module) for module in [ac.pi, ac.q])
logger.log('\nNumber of parameters: \t pi: %d, \t q: %d\n' % var_counts)
# Set up function for computing DDPG Q-loss
def compute_loss_q(data):
o, a, r, o2, d = data['obs'], data['act'], data['rew'], data['obs2'], data['done']
q = ac.q(o, a)
# Bellman backup for Q function
with torch.no_grad():
q_pi_targ = ac_targ.q(o2, ac_targ.pi(o2))
backup = r + gamma * (1 - d) * q_pi_targ
# MSE loss against Bellman backup
loss_q = ((q - backup) ** 2).mean()
# Useful info for logging
loss_info = dict(QVals=q.detach().numpy())
return loss_q, loss_info
# Set up function for computing DDPG pi loss
def compute_loss_pi(data):
o = data['obs']
q_pi = ac.q(o, ac.pi(o))
return -q_pi.mean()
# Set up optimizers for policy and q-function
pi_optimizer = Adam(ac.pi.parameters(), lr=pi_lr)
q_optimizer = Adam(ac.q.parameters(), lr=q_lr)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update(data):
# First run one gradient descent step for Q.
q_optimizer.zero_grad()
loss_q, loss_info = compute_loss_q(data)
loss_q.backward()
q_optimizer.step()
# Freeze Q-network so you don't waste computational effort
# computing gradients for it during the policy learning step.
for p in ac.q.parameters():
p.requires_grad = False
# Next run one gradient descent step for pi.
pi_optimizer.zero_grad()
loss_pi = compute_loss_pi(data)
loss_pi.backward()
pi_optimizer.step()
# Unfreeze Q-network so you can optimize it at next DDPG step.
for p in ac.q.parameters():
p.requires_grad = True
# Record things
logger.store(LossQ=loss_q.item(), LossPi=loss_pi.item(), **loss_info)
# Finally, update target networks by polyak averaging.
with torch.no_grad():
for p, p_targ in zip(ac.parameters(), ac_targ.parameters()):
# NB: We use an in-place operations "mul_", "add_" to update target
# params, as opposed to "mul" and "add", which would make new tensors.
p_targ.data.mul_(polyak)
p_targ.data.add_((1 - polyak) * p.data)
def get_action(o, noise_scale):
a = ac.act(torch.as_tensor(o, dtype=torch.float32))
a += noise_scale * np.random.randn(act_dim)
return np.clip(a, -act_limit, act_limit)
# def test_agent():
# for j in range(num_test_episodes):
# o, d, ep_ret, ep_len = test_env.reset(), False, 0, 0
# while not (d or (ep_len == max_ep_len)):
# # Take deterministic actions at test time (noise_scale=0)
# o, r, d, _ = test_env.step(get_action(o, 0))
# ep_ret += r
# ep_len += 1
# logger.store(TestEpRet=ep_ret, TestEpLen=ep_len)
# Prepare for interaction with environment
total_steps = steps_per_epoch * epochs
start_time = time.time()
o, ep_ret, ep_len, r, d = env.reset(), 0, 0, 0, False
# init trajectory saving (obs,action, reward, done)
trajectories = []
# Main loop: collect experience in env and update/log each epoch
for t in range(total_steps):
# Until start_steps have elapsed, randomly sample actions
# from a uniform distribution for better exploration. Afterwards,
# use the learned policy (with some noise, via act_noise).
if t > start_steps:
a = get_action(o, act_noise)
else:
a = env.action_space.sample()
# save step to trajectory
trajectories.append((o, a, r, d))
# Step the env
o2, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
# Ignore the "done" signal if it comes from hitting the time
# horizon (that is, when it's an artificial terminal signal
# that isn't based on the agent's state)
d = True if ep_len == max_ep_len else d
# Store experience to replay buffer
replay_buffer.store(o, a, r, o2, d)
# Super critical, easy to overlook step: make sure to update
# most recent observation!
o = o2
# End of trajectory handling
if d or (ep_len == max_ep_len):
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Update handling
if t >= update_after and t % update_every == 0:
for _ in range(update_every):
batch = replay_buffer.sample_batch(batch_size)
update(data=batch)
# End of epoch handling
if (t + 1) % steps_per_epoch == 0:
epoch = (t + 1) // steps_per_epoch
# Save model
if (epoch % save_freq == 0) or (epoch == epochs):
logger.save_state({'env': env}, None)
# # Test the performance of the deterministic version of the agent.
# test_agent()
#
# # Log info about epoch
# logger.log_tabular('Epoch', epoch)
# logger.log_tabular('EpRet', with_min_and_max=True)
# logger.log_tabular('TestEpRet', with_min_and_max=True)
# logger.log_tabular('EpLen', average_only=True)
# logger.log_tabular('TestEpLen', average_only=True)
# logger.log_tabular('TotalEnvInteracts', t)
# logger.log_tabular('QVals', with_min_and_max=True)
# logger.log_tabular('LossPi', average_only=True)
# logger.log_tabular('LossQ', average_only=True)
# logger.log_tabular('Time', time.time() - start_time)
# logger.dump_tabular()
np.save(str(trajectory_output_path) + '.npy', np.asarray(trajectories))
def vpg(env_fn,
actor_critic=core.MLPActorCritic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=50,
gamma=0.99,
pi_lr=3e-4,
vf_lr=1e-3,
train_v_iters=80,
lam=0.97,
max_ep_len=1000,
logger_kwargs=dict(),
save_freq=10):
"""
Vanilla Policy Gradient
(with GAE-Lambda for advantage estimation)
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: The constructor method for a PyTorch Module with a
``step`` method, an ``act`` method, a ``pi`` module, and a ``v``
module. The ``step`` method should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``a`` (batch, act_dim) | Numpy array of actions for each
| observation.
``v`` (batch,) | Numpy array of value estimates
| for the provided observations.
``logp_a`` (batch,) | Numpy array of log probs for the
| actions in ``a``.
=========== ================ ======================================
The ``act`` method behaves the same as ``step`` but only returns ``a``.
The ``pi`` module's forward call should accept a batch of
observations and optionally a batch of actions, and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` N/A | Torch Distribution object, containing
| a batch of distributions describing
| the policy for the provided observations.
``logp_a`` (batch,) | Optional (only returned if batch of
| actions is given). Tensor containing
| the log probability, according to
| the policy, of the provided actions.
| If actions not given, will contain
| ``None``.
=========== ================ ======================================
The ``v`` module's forward call should accept a batch of observations
and return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``v`` (batch,) | Tensor containing the value estimates
| for the provided observations. (Critical:
| make sure to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the ActorCritic object
you provided to VPG.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
# Special function to avoid certain slowdowns from PyTorch + MPI combo.
setup_pytorch_for_mpi()
# Set up logger and save configuration
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
# Random seed
seed += 10000 * proc_id()
torch.manual_seed(seed)
np.random.seed(seed)
# Instantiate environment
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
# Create actor-critic module
ac = actor_critic(env.observation_space, env.action_space, **ac_kwargs)
# Sync params across processes
sync_params(ac)
# Count variables
var_counts = tuple(core.count_vars(module) for module in [ac.pi, ac.v])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n' % var_counts)
# Set up experience buffer
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = VPGBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# Set up function for computing VPG policy loss
def compute_loss_pi(data):
obs, act, adv, logp_old = data['obs'], data['act'], data['adv'], data[
'logp']
# Policy loss
pi, logp = ac.pi(obs, act)
loss_pi = -(logp * adv).mean()
# Useful extra info
approx_kl = (logp_old - logp).mean().item()
ent = pi.entropy().mean().item()
pi_info = dict(kl=approx_kl, ent=ent)
return loss_pi, pi_info
# Set up function for computing value loss
def compute_loss_v(data):
obs, ret = data['obs'], data['ret']
return ((ac.v(obs) - ret)**2).mean()
# Set up optimizers for policy and value function
pi_optimizer = Adam(ac.pi.parameters(), lr=pi_lr)
vf_optimizer = Adam(ac.v.parameters(), lr=vf_lr)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update():
data = buf.get()
# Get loss and info values before update
pi_l_old, pi_info_old = compute_loss_pi(data)
pi_l_old = pi_l_old.item()
v_l_old = compute_loss_v(data).item()
# Train policy with a single step of gradient descent
pi_optimizer.zero_grad()
loss_pi, pi_info = compute_loss_pi(data)
loss_pi.backward()
mpi_avg_grads(ac.pi) # average grads across MPI processes
pi_optimizer.step()
# Value function learning
for i in range(train_v_iters):
vf_optimizer.zero_grad()
loss_v = compute_loss_v(data)
loss_v.backward()
mpi_avg_grads(ac.v) # average grads across MPI processes
vf_optimizer.step()
# Log changes from update
kl, ent = pi_info['kl'], pi_info_old['ent']
logger.store(LossPi=pi_l_old,
LossV=v_l_old,
KL=kl,
Entropy=ent,
DeltaLossPi=(loss_pi.item() - pi_l_old),
DeltaLossV=(loss_v.item() - v_l_old))
# Prepare for interaction with environment
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
a, v, logp = ac.step(torch.as_tensor(o, dtype=torch.float32))
next_o, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
# save and log
buf.store(o, a, r, v, logp)
logger.store(VVals=v)
# Update obs (critical!)
o = next_o
timeout = ep_len == max_ep_len
terminal = d or timeout
epoch_ended = t == local_steps_per_epoch - 1
if terminal or epoch_ended:
if epoch_ended and not (terminal):
print('Warning: trajectory cut off by epoch at %d steps.' %
ep_len,
flush=True)
# if trajectory didn't reach terminal state, bootstrap value target
if timeout or epoch_ended:
_, v, _ = ac.step(torch.as_tensor(o, dtype=torch.float32))
else:
v = 0
buf.finish_path(v)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None)
# Perform VPG update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch + 1) * steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
def vpg(env_fn, actor_critic=core.mlp_actor_critic, ac_kwargs=dict(), seed=0,
steps_per_epoch=4000, epochs=50, gamma=0.99, pi_lr=3e-4,
vf_lr=1e-3, train_v_iters=80, lam=0.97, max_ep_len=1000,
logger_kwargs=dict(), save_freq=10):
"""
Vanilla Policy Gradient
(with GAE-Lambda for advantage estimation)
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp`` (batch,) | Gives log probability, according to
| the policy, of taking actions ``a_ph``
| in states ``x_ph``.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``.
``v`` (batch,) | Gives the value estimate for states
| in ``x_ph``. (Critical: make sure
| to flatten this!)
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to VPG.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
pi_lr (float): Learning rate for policy optimizer.
vf_lr (float): Learning rate for value function optimizer.
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
seed += 10000 * proc_id()
tf.set_random_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
# Share information about action space with policy architecture
ac_kwargs['action_space'] = env.action_space
# Inputs to computation graph
x_ph, a_ph = core.placeholders_from_spaces(env.observation_space, env.action_space)
adv_ph, ret_ph, logp_old_ph = core.placeholders(None, None, None)
# Main outputs from computation graph
pi, logp, logp_pi, v = actor_critic(x_ph, a_ph, **ac_kwargs)
# Need all placeholders in *this* order later (to zip with data from buffer)
all_phs = [x_ph, a_ph, adv_ph, ret_ph, logp_old_ph]
# Every step, get: action, value, and logprob
get_action_ops = [pi, v, logp_pi]
# Experience buffer
local_steps_per_epoch = int(steps_per_epoch / num_procs())
buf = VPGBuffer(obs_dim, act_dim, local_steps_per_epoch, gamma, lam)
# Count variables
var_counts = tuple(core.count_vars(scope) for scope in ['pi', 'v'])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n'%var_counts)
# VPG objectives
pi_loss = -tf.reduce_mean(logp * adv_ph)
v_loss = tf.reduce_mean((ret_ph - v)**2)
# Info (useful to watch during learning)
approx_kl = tf.reduce_mean(logp_old_ph - logp) # a sample estimate for KL-divergence, easy to compute
approx_ent = tf.reduce_mean(-logp) # a sample estimate for entropy, also easy to compute
# Optimizers
train_pi = MpiAdamOptimizer(learning_rate=pi_lr).minimize(pi_loss)
train_v = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
logger.setup_tf_saver(sess, inputs={'x': x_ph}, outputs={'pi': pi, 'v': v})
def update():
inputs = {k:v for k,v in zip(all_phs, buf.get())}
pi_l_old, v_l_old, ent = sess.run([pi_loss, v_loss, approx_ent], feed_dict=inputs)
# Policy gradient step
sess.run(train_pi, feed_dict=inputs)
# Value function learning
for _ in range(train_v_iters):
sess.run(train_v, feed_dict=inputs)
# Log changes from update
pi_l_new, v_l_new, kl = sess.run([pi_loss, v_loss, approx_kl], feed_dict=inputs)
logger.store(LossPi=pi_l_old, LossV=v_l_old,
KL=kl, Entropy=ent,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
a, v_t, logp_t = sess.run(get_action_ops, feed_dict={x_ph: o.reshape(1,-1)})
o2, r, d, _ = env.step(a[0])
ep_ret += r
ep_len += 1
# save and log
buf.store(o, a, r, v_t, logp_t)
logger.store(VVals=v_t)
# Update obs (critical!)
o = o2
terminal = d or (ep_len == max_ep_len)
if terminal or (t==local_steps_per_epoch-1):
if not(terminal):
print('Warning: trajectory cut off by epoch at %d steps.'%ep_len)
# if trajectory didn't reach terminal state, bootstrap value target
last_val = 0 if d else sess.run(v, feed_dict={x_ph: o.reshape(1,-1)})
buf.finish_path(last_val)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Save model
if (epoch % save_freq == 0) or (epoch == epochs-1):
logger.save_state({'env': env}, None)
# Perform VPG update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch+1)*steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('Entropy', average_only=True)
logger.log_tabular('KL', average_only=True)
logger.log_tabular('Time', time.time()-start_time)
logger.dump_tabular()
def sac(env_fn,
actor_critic=core.MLPActorCritic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=100,
replay_size=int(1e6),
gamma=0.99,
polyak=0.995,
lr=1e-3,
alpha=0.2,
batch_size=100,
start_steps=10000,
update_after=1000,
update_every=50,
num_test_episodes=10,
max_ep_len=1000,
logger_kwargs=dict(),
save_freq=1):
"""
Soft Actor-Critic (SAC)
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: The constructor method for a PyTorch Module with an ``act``
method, a ``pi`` module, a ``q1`` module, and a ``q2`` module.
The ``act`` method and ``pi`` module should accept batches of
observations as inputs, and ``q1`` and ``q2`` should accept a batch
of observations and a batch of actions as inputs. When called,
``act``, ``q1``, and ``q2`` should return:
=========== ================ ======================================
Call Output Shape Description
=========== ================ ======================================
``act`` (batch, act_dim) | Numpy array of actions for each
| observation.
``q1`` (batch,) | Tensor containing one current estimate
| of Q* for the provided observations
| and actions. (Critical: make sure to
| flatten this!)
``q2`` (batch,) | Tensor containing the other current
| estimate of Q* for the provided observations
| and actions. (Critical: make sure to
| flatten this!)
=========== ================ ======================================
Calling ``pi`` should return:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``a`` (batch, act_dim) | Tensor containing actions from policy
| given observations.
``logp_pi`` (batch,) | Tensor containing log probabilities of
| actions in ``a``. Importantly: gradients
| should be able to flow back into ``a``.
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the ActorCritic object
you provided to SAC.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs to run and train agent.
replay_size (int): Maximum length of replay buffer.
gamma (float): Discount factor. (Always between 0 and 1.)
polyak (float): Interpolation factor in polyak averaging for target
networks. Target networks are updated towards main networks
according to:
.. math:: \\theta_{\\text{targ}} \\leftarrow
\\rho \\theta_{\\text{targ}} + (1-\\rho) \\theta
where :math:`\\rho` is polyak. (Always between 0 and 1, usually
close to 1.)
lr (float): Learning rate (used for both policy and value learning).
alpha (float): Entropy regularization coefficient. (Equivalent to
inverse of reward scale in the original SAC paper.)
batch_size (int): Minibatch size for SGD.
start_steps (int): Number of steps for uniform-random action selection,
before running real policy. Helps exploration.
update_after (int): Number of env interactions to collect before
starting to do gradient descent updates. Ensures replay buffer
is full enough for useful updates.
update_every (int): Number of env interactions that should elapse
between gradient descent updates. Note: Regardless of how long
you wait between updates, the ratio of env steps to gradient steps
is locked to 1.
num_test_episodes (int): Number of episodes to test the deterministic
policy at the end of each epoch.
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
torch.manual_seed(seed)
np.random.seed(seed)
env, test_env = env_fn(), env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape[0]
# Action limit for clamping: critically, assumes all dimensions share the same bound!
act_limit = env.action_space.high[0]
# Create actor-critic module and target networks
if inspect.isclass(actor_critic):
ac = actor_critic(env.observation_space, env.action_space, **ac_kwargs)
else:
ac = actor_critic
ac_targ = deepcopy(ac)
# Freeze target networks with respect to optimizers (only update via polyak averaging)
for p in ac_targ.parameters():
p.requires_grad = False
# List of parameters for both Q-networks (save this for convenience)
q_params = itertools.chain(ac.q1.parameters(), ac.q2.parameters())
# Experience buffer
replay_buffer = ReplayBuffer(obs_dim=obs_dim,
act_dim=act_dim,
size=replay_size)
# Count variables (protip: try to get a feel for how different size networks behave!)
var_counts = tuple(
core.count_vars(module) for module in [ac.pi, ac.q1, ac.q2])
logger.log('\nNumber of parameters: \t pi: %d, \t q1: %d, \t q2: %d\n' %
var_counts)
# Set up function for computing SAC Q-losses
def compute_loss_q(data):
o, a, r, o2, d = data['obs'], data['act'], data['rew'], data[
'obs2'], data['done']
q1 = ac.q1(o, a)
q2 = ac.q2(o, a)
# Bellman backup for Q functions
with torch.no_grad():
# Target actions come from *current* policy
a2, logp_a2 = ac.pi(o2)
# Target Q-values
q1_pi_targ = ac_targ.q1(o2, a2)
q2_pi_targ = ac_targ.q2(o2, a2)
q_pi_targ = torch.min(q1_pi_targ, q2_pi_targ)
backup = r + gamma * (1 - d) * (q_pi_targ - alpha * logp_a2)
# MSE loss against Bellman backup
loss_q1 = ((q1 - backup)**2).mean()
loss_q2 = ((q2 - backup)**2).mean()
loss_q = loss_q1 + loss_q2
# Useful info for logging
q_info = dict(Q1Vals=q1.detach().numpy(), Q2Vals=q2.detach().numpy())
return loss_q, q_info
# Set up function for computing SAC pi loss
def compute_loss_pi(data):
o = data['obs']
pi, logp_pi = ac.pi(o)
q1_pi = ac.q1(o, pi)
q2_pi = ac.q2(o, pi)
q_pi = torch.min(q1_pi, q2_pi)
# Entropy-regularized policy loss
loss_pi = (alpha * logp_pi - q_pi).mean()
# Useful info for logging
pi_info = dict(LogPi=logp_pi.detach().numpy())
return loss_pi, pi_info
# Set up optimizers for policy and q-function
pi_optimizer = Adam(ac.pi.parameters(), lr=lr)
q_optimizer = Adam(q_params, lr=lr)
# Set up model saving
logger.setup_pytorch_saver(ac)
def update(data):
# First run one gradient descent step for Q1 and Q2
q_optimizer.zero_grad()
loss_q, q_info = compute_loss_q(data)
loss_q.backward()
q_optimizer.step()
# Record things
logger.store(LossQ=loss_q.item(), **q_info)
# Freeze Q-networks so you don't waste computational effort
# computing gradients for them during the policy learning step.
for p in q_params:
p.requires_grad = False
# Next run one gradient descent step for pi.
pi_optimizer.zero_grad()
loss_pi, pi_info = compute_loss_pi(data)
loss_pi.backward()
pi_optimizer.step()
# Unfreeze Q-networks so you can optimize it at next DDPG step.
for p in q_params:
p.requires_grad = True
# Record things
logger.store(LossPi=loss_pi.item(), **pi_info)
# Finally, update target networks by polyak averaging.
with torch.no_grad():
for p, p_targ in zip(ac.parameters(), ac_targ.parameters()):
# NB: We use an in-place operations "mul_", "add_" to update target
# params, as opposed to "mul" and "add", which would make new tensors.
p_targ.data.mul_(polyak)
p_targ.data.add_((1 - polyak) * p.data)
def get_action(o, deterministic=False):
return ac.act(torch.as_tensor(o, dtype=torch.float32), deterministic)
def test_agent():
for j in range(num_test_episodes):
o, d, ep_ret, ep_len = test_env.reset(), False, 0, 0
while not (d or (ep_len == max_ep_len)):
# Take deterministic actions at test time
o, r, d, _ = test_env.step(get_action(o, True))
ep_ret += r
ep_len += 1
logger.store(TestEpRet=ep_ret, TestEpLen=ep_len)
# Prepare for interaction with environment
total_steps = steps_per_epoch * epochs
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
# Main loop: collect experience in env and update/log each epoch
for t in range(total_steps):
# Until start_steps have elapsed, randomly sample actions
# from a uniform distribution for better exploration. Afterwards,
# use the learned policy.
if t > start_steps:
a = get_action(o)
else:
a = env.action_space.sample()
# Step the env
o2, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
# Ignore the "done" signal if it comes from hitting the time
# horizon (that is, when it's an artificial terminal signal
# that isn't based on the agent's state)
d = False if ep_len == max_ep_len else d
# Store experience to replay buffer
replay_buffer.store(o, a, r, o2, d)
# Super critical, easy to overlook step: make sure to update
# most recent observation!
o = o2
# End of trajectory handling
if d or (ep_len == max_ep_len):
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Update handling
if t >= update_after and t % update_every == 0:
for j in range(update_every):
batch = replay_buffer.sample_batch(batch_size)
update(data=batch)
# End of epoch handling
if (t + 1) % steps_per_epoch == 0:
epoch = (t + 1) // steps_per_epoch
# Save model
if (epoch % save_freq == 0) or (epoch == epochs - 1):
logger.save_state({'env': env}, None) # current state
logger.save_state({'env': env}, epoch) # for rendering
# Test the performance of the deterministic version of the agent.
test_agent()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('TestEpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('TestEpLen', average_only=True)
logger.log_tabular('TotalEnvInteracts', t)
logger.log_tabular('Q1Vals', with_min_and_max=True)
logger.log_tabular('Q2Vals', with_min_and_max=True)
logger.log_tabular('LogPi', with_min_and_max=True)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossQ', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()
logger.output_file.close()
def __init__(self,
env_fn,
actor_critic=core.mlp_actor_critic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=100,
replay_size=int(1e6),
gamma=0.99,
polyak=0.995,
lr=1e-3,
alpha=0.2,
batch_size=100,
start_steps=10000,
update_after=1000,
update_every=50,
num_test_episodes=10,
max_ep_len=1000,
logger_kwargs=dict(),
save_freq=1):
"""
Soft Actor-Critic (SAC)
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``mu`` (batch, act_dim) | Computes mean actions from policy
| given states.
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``. Critical: must be differentiable
| with respect to policy parameters all
| the way through action sampling.
``q1`` (batch,) | Gives one estimate of Q* for
| states in ``x_ph`` and actions in
| ``a_ph``.
``q2`` (batch,) | Gives another estimate of Q* for
| states in ``x_ph`` and actions in
| ``a_ph``.
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to SAC.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs to run and train agent.
replay_size (int): Maximum length of replay buffer.
gamma (float): Discount factor. (Always between 0 and 1.)
polyak (float): Interpolation factor in polyak averaging for target
networks. Target networks are updated towards main networks
according to:
.. math:: \\theta_{\\text{targ}} \\leftarrow
\\rho \\theta_{\\text{targ}} + (1-\\rho) \\theta
where :math:`\\rho` is polyak. (Always between 0 and 1, usually
close to 1.)
lr (float): Learning rate (used for both policy and value learning).
alpha (float): Entropy regularization coefficient. (Equivalent to
inverse of reward scale in the original SAC paper.)
batch_size (int): Minibatch size for SGD.
start_steps (int): Number of steps for uniform-random action selection,
before running real policy. Helps exploration.
update_after (int): Number of env interactions to collect before
starting to do gradient descent updates. Ensures replay buffer
is full enough for useful updates.
update_every (int): Number of env interactions that should elapse
between gradient descent updates. Note: Regardless of how long
you wait between updates, the ratio of env steps to gradient steps
is locked to 1.
num_test_episodes (int): Number of episodes to test the deterministic
policy at the end of each epoch.
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
super(SAC, self).__init__()
self.alpha = alpha
self.gamma = gamma
self.steps_per_epoch = steps_per_epoch
self.epochs = epochs
self.start_steps = start_steps
self.max_ep_len = max_ep_len
self.update_after = update_after
self.update_every = update_every
self.batch_size = batch_size
self.save_freq = save_freq
self.num_test_episodes = num_test_episodes
self.polyak = polyak
self.logger = EpochLogger(**logger_kwargs)
self.logger.save_config(locals())
tf.compat.v1.set_random_seed(seed)
np.random.seed(seed)
self.env, self.test_env = env_fn(), env_fn()
obs_dim = self.env.observation_space.shape[0]
act_dim = self.env.action_space.shape[0]
# Action limit for clamping: critically, assumes all dimensions share the same bound!
act_limit = self.env.action_space.high[0]
# Share information about action space with policy architecture
ac_kwargs['action_space'] = self.env.action_space
# Main outputs from computation graph
self.policy, self.Q1, self.Q2 = actor_critic(obs_dim,
act_dim,
name='main',
**ac_kwargs)
_, self.Q1_targ, self.Q2_targ = actor_critic(obs_dim,
act_dim,
name='target',
**ac_kwargs)
# Experience buffer
self.replay_buffer = ReplayBuffer(obs_dim=obs_dim,
act_dim=act_dim,
size=replay_size)
self.policy_optimizer = tf.keras.optimizers.Adam(learning_rate=lr)
self.value_optimizer = tf.keras.optimizers.Adam(learning_rate=lr)
self.target_init()
parser.add_argument('--is_clip_v', action="store_true")
parser.add_argument('--last_v', action="store_true")
parser.add_argument('--is_gae', action="store_true")
parser.add_argument('--max_grad_norm', default=-1, type=float)
parser.add_argument('--anneal_lr', action="store_true")
parser.add_argument('--debug', action="store_false")
parser.add_argument('--log_every', default=5, type=int)
parser.add_argument('--target_kl', default=0.03, type=float)
args = parser.parse_args()
device = torch.device(
"cuda:" + str(args.gpu) if torch.cuda.is_available() else "cpu")
from utils.utils import setup_logger_kwargs
logger_kwargs = setup_logger_kwargs(args.exp_name, args.seed)
logger = EpochLogger(**logger_kwargs)
with open(os.path.join(logger.output_dir, 'args.json'), 'w') as f:
json.dump(vars(args), f, sort_keys=True, indent=4)
writer = SummaryWriter(os.path.join(logger.output_dir, "logs"))
scenario_root = (Path(__file__).parent / "../dataset_public").resolve()
scenario_paths = [
scenario for scenario_dir in scenario_root.iterdir()
for scenario in scenario_dir.iterdir() if scenario.is_dir()
]
print(f"training on {scenario_paths}")
AGENT_ID = "Agent-007"
env = gym.make(
def trpo(env_fn, actor_critic=core.mlp_actor_critic, ac_kwargs=dict(), seed=0,
steps_per_epoch=4000, epochs=50, gamma=0.99, delta=0.01, vf_lr=1e-3,
train_v_iters=80, damping_coeff=0.1, cg_iters=10, backtrack_iters=10,
backtrack_coeff=0.8, lam=0.97, max_ep_len=1000, logger_kwargs=dict(),
save_freq=10, algo='trpo'):
"""
Trust Region Policy Optimization
(with support for Natural Policy Gradient)
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
============ ================ ========================================
Symbol Shape Description
============ ================ ========================================
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp`` (batch,) | Gives log probability, according to
| the policy, of taking actions ``a_ph``
| in states ``x_ph``.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``.
``info`` N/A | A dict of any intermediate quantities
| (from calculating the policy or log
| probabilities) which are needed for
| analytically computing KL divergence.
| (eg sufficient statistics of the
| distributions)
``info_phs`` N/A | A dict of placeholders for old values
| of the entries in ``info``.
``d_kl`` () | A symbol for computing the mean KL
| divergence between the current policy
| (``pi``) and the old policy (as
| specified by the inputs to
| ``info_phs``) over the batch of
| states given in ``x_ph``.
``v`` (batch,) | Gives the value estimate for states
| in ``x_ph``. (Critical: make sure
| to flatten this!)
============ ================ ========================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to TRPO.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs of interaction (equivalent to
number of policy updates) to perform.
gamma (float): Discount factor. (Always between 0 and 1.)
delta (float): KL-divergence limit for TRPO / NPG update.
(Should be small for stability. Values like 0.01, 0.05.)
vf_lr (float): Learning rate for value function optimizer.
train_v_iters (int): Number of gradient descent steps to take on
value function per epoch.
damping_coeff (float): Artifact for numerical stability, should be
smallish. Adjusts Hessian-vector product calculation:
.. math:: Hv \\rightarrow (\\alpha I + H)v
where :math:`\\alpha` is the damping coefficient.
Probably don't play with this hyperparameter.
cg_iters (int): Number of iterations of conjugate gradient to perform.
Increasing this will lead to a more accurate approximation
to :math:`H^{-1} g`, and possibly slightly-improved performance,
but at the cost of slowing things down.
Also probably don't play with this hyperparameter.
backtrack_iters (int): Maximum number of steps allowed in the
backtracking line search. Since the line search usually doesn't
backtrack, and usually only steps back once when it does, this
hyperparameter doesn't often matter.
backtrack_coeff (float): How far back to step during backtracking line
search. (Always between 0 and 1, usually above 0.5.)
lam (float): Lambda for GAE-Lambda. (Always between 0 and 1,
close to 1.)
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
algo: Either 'trpo' or 'npg': this code supports both, since they are
almost the same.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
seed += 10000 * proc_id()
tf.set_random_seed(seed)
np.random.seed(seed)
env = env_fn()
obs_dim = env.observation_space.shape
act_dim = env.action_space.shape
# Share information about action space with policy architecture
ac_kwargs['action_space'] = env.action_space
# Inputs to computation graph
x_ph, a_ph = core.placeholders_from_spaces(env.observation_space, env.action_space)
adv_ph, ret_ph, logp_old_ph = core.placeholders(None, None, None)
# Main outputs from computation graph, plus placeholders for old pdist (for KL)
pi, logp, logp_pi, info, info_phs, d_kl, v = actor_critic(x_ph, a_ph, **ac_kwargs)
# Need all placeholders in *this* order later (to zip with data from buffer)
all_phs = [x_ph, a_ph, adv_ph, ret_ph, logp_old_ph] + core.values_as_sorted_list(info_phs)
# Every step, get: action, value, logprob, & info for pdist (for computing kl div)
get_action_ops = [pi, v, logp_pi] + core.values_as_sorted_list(info)
# Experience buffer
local_steps_per_epoch = int(steps_per_epoch / num_procs())
info_shapes = {k: v.shape.as_list()[1:] for k,v in info_phs.items()}
buf = GAEBuffer(obs_dim, act_dim, local_steps_per_epoch, info_shapes, gamma, lam)
# Count variables
var_counts = tuple(core.count_vars(scope) for scope in ['pi', 'v'])
logger.log('\nNumber of parameters: \t pi: %d, \t v: %d\n'%var_counts)
# TRPO losses
ratio = tf.exp(logp - logp_old_ph) # pi(a|s) / pi_old(a|s)
pi_loss = -tf.reduce_mean(ratio * adv_ph)
v_loss = tf.reduce_mean((ret_ph - v)**2)
# Optimizer for value function
train_vf = MpiAdamOptimizer(learning_rate=vf_lr).minimize(v_loss)
# Symbols needed for CG solver
pi_params = core.get_vars('pi')
gradient = core.flat_grad(pi_loss, pi_params)
v_ph, hvp = core.hessian_vector_product(d_kl, pi_params)
if damping_coeff > 0:
hvp += damping_coeff * v_ph
# Symbols for getting and setting params
get_pi_params = core.flat_concat(pi_params)
set_pi_params = core.assign_params_from_flat(v_ph, pi_params)
sess = tf.Session()
sess.run(tf.global_variables_initializer())
# Sync params across processes
sess.run(sync_all_params())
# Setup model saving
logger.setup_tf_saver(sess, inputs={'x': x_ph}, outputs={'pi': pi, 'v': v})
def cg(Ax, b):
"""
Conjugate gradient algorithm
(see https://en.wikipedia.org/wiki/Conjugate_gradient_method)
"""
x = np.zeros_like(b)
r = b.copy() # Note: should be 'b - Ax(x)', but for x=0, Ax(x)=0. Change if doing warm start.
p = r.copy()
r_dot_old = np.dot(r,r)
for _ in range(cg_iters):
z = Ax(p)
alpha = r_dot_old / (np.dot(p, z) + EPS)
x += alpha * p
r -= alpha * z
r_dot_new = np.dot(r,r)
p = r + (r_dot_new / r_dot_old) * p
r_dot_old = r_dot_new
return x
def update():
# Prepare hessian func, gradient eval
inputs = {k:v for k,v in zip(all_phs, buf.get())}
Hx = lambda x : mpi_avg(sess.run(hvp, feed_dict={**inputs, v_ph: x}))
g, pi_l_old, v_l_old = sess.run([gradient, pi_loss, v_loss], feed_dict=inputs)
g, pi_l_old = mpi_avg(g), mpi_avg(pi_l_old)
# Core calculations for TRPO or NPG
x = cg(Hx, g)
alpha = np.sqrt(2*delta/(np.dot(x, Hx(x))+EPS))
old_params = sess.run(get_pi_params)
def set_and_eval(step):
sess.run(set_pi_params, feed_dict={v_ph: old_params - alpha * x * step})
return mpi_avg(sess.run([d_kl, pi_loss], feed_dict=inputs))
if algo=='npg':
# npg has no backtracking or hard kl constraint enforcement
kl, pi_l_new = set_and_eval(step=1.)
elif algo=='trpo':
# trpo augments npg with backtracking line search, hard kl
for j in range(backtrack_iters):
kl, pi_l_new = set_and_eval(step=backtrack_coeff**j)
if kl <= delta and pi_l_new <= pi_l_old:
logger.log('Accepting new params at step %d of line search.'%j)
logger.store(BacktrackIters=j)
break
if j==backtrack_iters-1:
logger.log('Line search failed! Keeping old params.')
logger.store(BacktrackIters=j)
kl, pi_l_new = set_and_eval(step=0.)
# Value function updates
for _ in range(train_v_iters):
sess.run(train_vf, feed_dict=inputs)
v_l_new = sess.run(v_loss, feed_dict=inputs)
# Log changes from update
logger.store(LossPi=pi_l_old, LossV=v_l_old, KL=kl,
DeltaLossPi=(pi_l_new - pi_l_old),
DeltaLossV=(v_l_new - v_l_old))
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
# Main loop: collect experience in env and update/log each epoch
for epoch in range(epochs):
for t in range(local_steps_per_epoch):
agent_outs = sess.run(get_action_ops, feed_dict={x_ph: o.reshape(1,-1)})
a, v_t, logp_t, info_t = agent_outs[0][0], agent_outs[1], agent_outs[2], agent_outs[3:]
o2, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
# save and log
buf.store(o, a, r, v_t, logp_t, info_t)
logger.store(VVals=v_t)
# Update obs (critical!)
o = o2
terminal = d or (ep_len == max_ep_len)
if terminal or (t==local_steps_per_epoch-1):
if not(terminal):
print('Warning: trajectory cut off by epoch at %d steps.'%ep_len)
# if trajectory didn't reach terminal state, bootstrap value target
last_val = 0 if d else sess.run(v, feed_dict={x_ph: o.reshape(1,-1)})
buf.finish_path(last_val)
if terminal:
# only save EpRet / EpLen if trajectory finished
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Save model
if (epoch % save_freq == 0) or (epoch == epochs-1):
logger.save_state({'env': env}, None)
# Perform TRPO or NPG update!
update()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('VVals', with_min_and_max=True)
logger.log_tabular('TotalEnvInteracts', (epoch+1)*steps_per_epoch)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossV', average_only=True)
logger.log_tabular('DeltaLossPi', average_only=True)
logger.log_tabular('DeltaLossV', average_only=True)
logger.log_tabular('KL', average_only=True)
if algo=='trpo':
logger.log_tabular('BacktrackIters', average_only=True)
logger.log_tabular('Time', time.time()-start_time)
logger.dump_tabular()
def __init__(self,
env_name,
port=2000,
gpu=0,
train_step=25000,
evaluation_step=3000,
max_ep_len=6000,
alpha=0.35,
epsilon_train=0.1,
polyak=0.995,
start_steps=1000,
batch_size=100,
replay_size=50000,
iteration=200,
gamma=0.99,
act_noise=0.1,
target_noise=0.2,
noise_clip=0.5,
pi_lr=1e-4,
q_lr=1e-4,
policy_delay=2,
target_update_period=800,
update_period=4,
logger_kwargs=dict()):
self.logger = EpochLogger(**logger_kwargs)
self.logger.save_config(locals())
self.iteration = iteration
self.train_step = train_step
self.evaluation_step = evaluation_step
self.env = CarlaEnv(early_termination_enabled=True,
run_offscreen=False,
port=port,
gpu=gpu,
discrete_control=False)
self.obs_dim = self.env.observation_space.shape
self.act_dim = self.env.action_space.shape[0]
self.alpha = alpha
self.start_steps = start_steps
self.cur_train_step = 0
self.batch_size = batch_size
self.max_ep_len = max_ep_len
self.act_limit = self.env.action_space.high[0]
self.act_noise = act_noise
self.policy_delay = policy_delay
if debug_mode:
self.summary = tf.summary.FileWriter(
os.path.join(self.logger.output_dir, "logs"))
# self.obs_dim = (30, 30, 3)
# Inputs to computation graph
self.x_ph, self.a_ph, self.x2_ph, self.r_ph, self.d_ph = \
core.placeholders(self.obs_dim, self.act_dim, self.obs_dim, None, None)
self.actor_critic = core.ActorCritic(self.act_dim)
self.target_actor_critic = core.ActorCritic(self.act_dim)
self.q1, self.q2, self.pi = self.actor_critic([self.x_ph, self.a_ph])
self.q1_pi, _, _ = self.actor_critic([self.x_ph, self.pi])
tar_q1, tar_q2, _ = self.target_actor_critic([self.x_ph, self.a_ph])
_, _, pi_targ = self.target_actor_critic([self.x2_ph, self.a_ph])
epsilon = tf.random_normal(tf.shape(pi_targ), stddev=target_noise)
epsilon = tf.clip_by_value(epsilon, -noise_clip, noise_clip)
a2 = pi_targ + epsilon
a2 = tf.clip_by_value(a2, -self.act_limit, self.act_limit)
q1_targ, q2_targ, _ = self.target_actor_critic([self.x2_ph, a2])
# Main outputs from computation graph
# with tf.variable_scope('main'):
# # self.pi, self.q1, self.q2, q1_pi = core.cnn_actor_critic(self.x_ph, self.a_ph)
# self.pi, self.q1, = core.cnn_actor_critic(self.x_ph, self.a_ph)
# self.q2, q1_pi = self.pi, self.q1
# # Target policy network
# with tf.variable_scope('target'):
# pi_targ, _, _, _ = core.cnn_actor_critic(self.x2_ph, self.a_ph)
#
#
# # Target Q networks
# with tf.variable_scope('target', reuse=True):
# # Target policy smoothing, by adding clipped noise to target actions
# epsilon = tf.random_normal(tf.shape(pi_targ), stddev=target_noise)
# epsilon = tf.clip_by_value(epsilon, -noise_clip, noise_clip)
# a2 = pi_targ + epsilon
# a2 = tf.clip_by_value(a2, -self.act_limit, self.act_limit)
#
# # Target Q-values, using action from target policy
# _, q1_targ, q2_targ, _ = core.cnn_actor_critic(self.x2_ph, a2)
# q1_targ, q2_targ = q1_pi, q1_pi
# q3, q4 = q1_pi, q1_pi
self.replay_buffer = ReplayBuffer(replay_size)
# Bellman backup for Q functions, using Clipped Double-Q targets
min_q_targ = tf.minimum(q1_targ, q2_targ)
backup = tf.stop_gradient(self.r_ph + gamma *
(1 - self.d_ph) * min_q_targ)
# TD3 losses
self.pi_loss = -tf.reduce_mean(self.q1_pi)
q1_loss = tf.reduce_mean((self.q1 - backup)**2)
q2_loss = tf.reduce_mean((self.q2 - backup)**2)
self.q_loss = q1_loss + q2_loss
# Separate train ops for pi, q
pi_optimizer = tf.train.AdamOptimizer(learning_rate=pi_lr)
q_optimizer = tf.train.AdamOptimizer(learning_rate=q_lr)
# self.train_pi_op = pi_optimizer.minimize(self.pi_loss, var_list=get_vars('main/pi') + get_vars('main/cnn'))
# self.train_q_op = q_optimizer.minimize(self.q_loss, var_list=get_vars('main/q') + get_vars('main/cnn'))
self.train_pi_op = pi_optimizer.minimize(self.pi_loss)
self.train_q_op = q_optimizer.minimize(self.q_loss)
# var = [v.name for v in tf.global_variables()]
# v = tf.trainable_variables()
var = [v.name for v in tf.trainable_variables()]
print(var)
if debug_mode:
tf.summary.histogram("main/q1", self.q1)
tf.summary.histogram("main/q2", self.q2)
tf.summary.histogram("main/q1_pi", self.q1_pi)
tf.summary.histogram("target/tar_q1", tar_q1)
tf.summary.histogram("target/tar_q2", tar_q2)
tf.summary.histogram("target/q1_tar", q1_targ)
tf.summary.histogram("target/q2_tar", q2_targ)
tf.summary.histogram("a/pi", self.pi)
tf.summary.histogram("a/pi_tar", pi_targ)
tf.summary.histogram("a/a2", a2)
for var in tf.trainable_variables():
tf.summary.histogram(var.name, var)
tf.summary.scalar("loss_q1", q1_loss)
tf.summary.scalar("loss_q2", q2_loss)
tf.summary.scalar("loss_q", self.q_loss)
tf.summary.scalar("loss_pi", self.pi_loss)
self.merge = tf.summary.merge_all()
# Polyak averaging for target variables
# self.target_update = tf.group([tf.assign(v_targ, polyak*v_targ + (1-polyak)*v_main)
# for v_main, v_targ in zip(get_vars('main'), get_vars('target'))])
self.target_update = tf.group([
tf.assign(v_targ, polyak * v_targ + (1 - polyak) * v_main)
for v_main, v_targ in zip(
self.actor_critic.trainable_variables,
self.target_actor_critic.trainable_variables)
])
# Initializing targets to match main variables
# target_init = tf.group([tf.assign(v_targ, v_main)
# for v_main, v_targ in zip(get_vars('main'), get_vars('target'))])
target_init = tf.group([
tf.assign(v_targ, v_main) for v_main, v_targ in zip(
self.actor_critic.trainable_variables,
self.target_actor_critic.trainable_variables)
])
config = tf.ConfigProto(allow_soft_placement=True)
config.gpu_options.allow_growth = True
self.sess = tf.Session("", config=config)
self.sess.run(tf.global_variables_initializer())
self.sess.run(target_init)
self.saver = tf.train.Checkpoint(model=self.actor_critic)
self.savepath = os.path.join(self.logger.output_dir, "saver")
if not os.path.exists(self.savepath):
os.makedirs(self.savepath)
self.manager = tf.train.CheckpointManager(self.saver,
self.savepath,
max_to_keep=10)
np.random.seed(args.seed)
env.seed(args.seed)
state_dim = env.observation_space.shape
from utils.run_utils import setup_logger_kwargs
logger_kwargs = setup_logger_kwargs(args.exp_name, args.seed)
expert_data_file = os.path.join(logger_kwargs["output_dir"], "experts")
with open(
os.path.join(
expert_data_file, args.domain_name + "_" + args.task_name +
"_epoch" + str(args.expert_num) + ".pkl"), "rb") as f:
expert_data = pickle.load(f)
out_kwargs = setup_logger_kwargs(args.out_dir, args.seed)
logger = EpochLogger(**out_kwargs)
writer = SummaryWriter(os.path.join(logger.output_dir, "logs"))
with open(os.path.join(logger.output_dir, 'args.json'), 'w') as f:
json.dump(vars(args), f, sort_keys=True, indent=4)
if not os.path.exists(os.path.join(logger.output_dir, "checkpoints")):
os.makedirs(os.path.join(logger.output_dir, "checkpoints"))
encoder = PixelEncoder(state_dim, args.feature_dim,
num_layers=4).to(device)
decoder = PixelDecoder(state_dim, args.feature_dim,
num_layers=4).to(device)
encoder_optimizer = torch.optim.Adam(encoder.parameters(),
lr=args.encoder_lr)
decoder_optimizer = torch.optim.Adam(
decoder.parameters(),
lr=args.decoder_lr,
def __init__(self,
env_name,
port=2000,
gpu=0,
train_step=10000,
evaluation_step=3000,
max_ep_len=300,
polyak=0.995,
start_steps=2000,
batch_size=100,
replay_size=50000,
iteration=200,
gamma=0.99,
act_noise=0.1,
target_noise=0.2,
noise_clip=0.5,
pi_lr=1e-4,
q_lr=1e-3,
policy_delay=2,
logger_kwargs=dict()):
self.logger = EpochLogger(**logger_kwargs)
self.logger.save_config(locals())
self.iteration = iteration
self.train_step = train_step
self.evaluation_step = evaluation_step
self.env = CarlaEnv(early_termination_enabled=True,
run_offscreen=False,
port=port,
gpu=gpu,
discrete_control=False)
self.obs_dim = self.env.observation_space.shape
self.act_dim = self.env.action_space.shape[0]
self.start_steps = start_steps
self.cur_train_step = 0
self.cur_tensorboard_step = 0
self.batch_size = batch_size
self.max_ep_len = max_ep_len
self.act_limit = self.env.action_space.high[0]
self.act_noise = act_noise
self.target_noise = target_noise
self.noise_clip = noise_clip
self.policy_delay = policy_delay
self.polyak = polyak
self.gamma = gamma
self.opti_q = tf.keras.optimizers.Adam(q_lr)
self.opti_pi = tf.keras.optimizers.Adam(pi_lr)
if debug_mode:
self.summary = tf.summary.create_file_writer(
os.path.join(self.logger.output_dir, "logs"))
self.actor_critic = core.ActorCritic(self.act_dim, self.act_limit)
self.target_actor_critic = core.ActorCritic(self.act_dim,
self.act_limit)
self.replay_buffer = ReplayBuffer(replay_size)
with tf.GradientTape() as tape:
x = tf.random.uniform(minval=0, maxval=1, shape=self.obs_dim)
x = tf.expand_dims(x, axis=0)
a = tf.random.uniform(minval=0, maxval=1, shape=[self.act_dim])
a = tf.expand_dims(a, axis=0)
self.actor_critic([x, a])
self.actor_critic.choose_action(x)
self.target_actor_critic([x, a])
self.target_actor_critic.choose_action(x)
self.target_init(self.target_actor_critic, self.actor_critic)
self.savepath = os.path.join(self.logger.output_dir, "saver")
checkpoint = tf.train.Checkpoint(model=self.actor_critic,
target_model=self.target_actor_critic)
self.manager = tf.train.CheckpointManager(checkpoint,
directory=self.savepath,
max_to_keep=20,
checkpoint_name="model.ckpt")
def sac(env_fn,
actor_critic=core.mlp_actor_critic,
ac_kwargs=dict(),
seed=0,
steps_per_epoch=4000,
epochs=100,
replay_size=int(1e6),
gamma=0.99,
polyak=0.995,
lr=1e-3,
alpha=0.2,
batch_size=100,
start_steps=10000,
update_after=1000,
update_every=50,
num_test_episodes=10,
max_ep_len=1000,
logger_kwargs=dict(),
save_freq=1):
"""
Soft Actor-Critic (SAC)
Args:
env_fn : A function which creates a copy of the environment.
The environment must satisfy the OpenAI Gym API.
actor_critic: A function which takes in placeholder symbols
for state, ``x_ph``, and action, ``a_ph``, and returns the main
outputs from the agent's Tensorflow computation graph:
=========== ================ ======================================
Symbol Shape Description
=========== ================ ======================================
``mu`` (batch, act_dim) | Computes mean actions from policy
| given states.
``pi`` (batch, act_dim) | Samples actions from policy given
| states.
``logp_pi`` (batch,) | Gives log probability, according to
| the policy, of the action sampled by
| ``pi``. Critical: must be differentiable
| with respect to policy parameters all
| the way through action sampling.
``q1`` (batch,) | Gives one estimate of Q* for
| states in ``x_ph`` and actions in
| ``a_ph``.
``q2`` (batch,) | Gives another estimate of Q* for
| states in ``x_ph`` and actions in
| ``a_ph``.
=========== ================ ======================================
ac_kwargs (dict): Any kwargs appropriate for the actor_critic
function you provided to SAC.
seed (int): Seed for random number generators.
steps_per_epoch (int): Number of steps of interaction (state-action pairs)
for the agent and the environment in each epoch.
epochs (int): Number of epochs to run and train agent.
replay_size (int): Maximum length of replay buffer.
gamma (float): Discount factor. (Always between 0 and 1.)
polyak (float): Interpolation factor in polyak averaging for target
networks. Target networks are updated towards main networks
according to:
.. math:: \\theta_{\\text{targ}} \\leftarrow
\\rho \\theta_{\\text{targ}} + (1-\\rho) \\theta
where :math:`\\rho` is polyak. (Always between 0 and 1, usually
close to 1.)
lr (float): Learning rate (used for both policy and value learning).
alpha (float): Entropy regularization coefficient. (Equivalent to
inverse of reward scale in the original SAC paper.)
batch_size (int): Minibatch size for SGD.
start_steps (int): Number of steps for uniform-random action selection,
before running real policy. Helps exploration.
update_after (int): Number of env interactions to collect before
starting to do gradient descent updates. Ensures replay buffer
is full enough for useful updates.
update_every (int): Number of env interactions that should elapse
between gradient descent updates. Note: Regardless of how long
you wait between updates, the ratio of env steps to gradient steps
is locked to 1.
num_test_episodes (int): Number of episodes to test the deterministic
policy at the end of each epoch.
max_ep_len (int): Maximum length of trajectory / episode / rollout.
logger_kwargs (dict): Keyword args for EpochLogger.
save_freq (int): How often (in terms of gap between epochs) to save
the current policy and value function.
"""
logger = EpochLogger(**logger_kwargs)
logger.save_config(locals())
tf.set_random_seed(seed)
np.random.seed(seed)
env, test_env = env_fn(), env_fn()
obs_dim = env.observation_space.shape[0]
act_dim = env.action_space.shape[0]
# Action limit for clamping: critically, assumes all dimensions share the same bound!
act_limit = env.action_space.high[0]
# Share information about action space with policy architecture
ac_kwargs['action_space'] = env.action_space
# Inputs to computation graph
x_ph, a_ph, x2_ph, r_ph, d_ph = core.placeholders(obs_dim, act_dim,
obs_dim, None, None)
# Main outputs from computation graph
with tf.variable_scope('main'):
mu, pi, logp_pi, q1, q2 = actor_critic(x_ph, a_ph, **ac_kwargs)
with tf.variable_scope('main', reuse=True):
# compose q with pi, for pi-learning
_, _, _, q1_pi, q2_pi = actor_critic(x_ph, pi, **ac_kwargs)
# get actions and log probs of actions for next states, for Q-learning
_, pi_next, logp_pi_next, _, _ = actor_critic(x2_ph, a_ph, **ac_kwargs)
# Target value network
with tf.variable_scope('target'):
# target q values, using actions from *current* policy
_, _, _, q1_targ, q2_targ = actor_critic(x2_ph, pi_next, **ac_kwargs)
# Experience buffer
replay_buffer = ReplayBuffer(obs_dim=obs_dim,
act_dim=act_dim,
size=replay_size)
# Count variables
var_counts = tuple(
core.count_vars(scope)
for scope in ['main/pi', 'main/q1', 'main/q2', 'main'])
print(
'\nNumber of parameters: \t pi: %d, \t q1: %d, \t q2: %d, \t total: %d\n'
% var_counts)
# Min Double-Q:
min_q_pi = tf.minimum(q1_pi, q2_pi)
min_q_targ = tf.minimum(q1_targ, q2_targ)
# Entropy-regularized Bellman backup for Q functions, using Clipped Double-Q targets
q_backup = tf.stop_gradient(r_ph + gamma * (1 - d_ph) *
(min_q_targ - alpha * logp_pi_next))
# Soft actor-critic losses
pi_loss = tf.reduce_mean(alpha * logp_pi - min_q_pi)
q1_loss = 0.5 * tf.reduce_mean((q_backup - q1)**2)
q2_loss = 0.5 * tf.reduce_mean((q_backup - q2)**2)
value_loss = q1_loss + q2_loss
# Policy train op
# (has to be separate from value train op, because q1_pi appears in pi_loss)
pi_optimizer = tf.train.AdamOptimizer(learning_rate=lr)
train_pi_op = pi_optimizer.minimize(pi_loss, var_list=get_vars('main/pi'))
# Value train op
# (control dep of train_pi_op because sess.run otherwise evaluates in nondeterministic order)
value_optimizer = tf.train.AdamOptimizer(learning_rate=lr)
value_params = get_vars('main/q')
with tf.control_dependencies([train_pi_op]):
train_value_op = value_optimizer.minimize(value_loss,
var_list=value_params)
# Polyak averaging for target variables
# (control flow because sess.run otherwise evaluates in nondeterministic order)
with tf.control_dependencies([train_value_op]):
target_update = tf.group([
tf.assign(v_targ, polyak * v_targ + (1 - polyak) * v_main)
for v_main, v_targ in zip(get_vars('main'), get_vars('target'))
])
# All ops to call during one training step
step_ops = [
pi_loss, q1_loss, q2_loss, q1, q2, logp_pi, train_pi_op,
train_value_op, target_update
]
# Initializing targets to match main variables
target_init = tf.group([
tf.assign(v_targ, v_main)
for v_main, v_targ in zip(get_vars('main'), get_vars('target'))
])
sess = tf.Session()
sess.run(tf.global_variables_initializer())
sess.run(target_init)
# Setup model saving
logger.setup_tf_saver(sess,
inputs={
'x': x_ph,
'a': a_ph
},
outputs={
'mu': mu,
'pi': pi,
'q1': q1,
'q2': q2
})
def get_action(o, deterministic=False):
act_op = mu if deterministic else pi
return sess.run(act_op, feed_dict={x_ph: o.reshape(1, -1)})[0]
def test_agent():
for j in range(num_test_episodes):
o, d, ep_ret, ep_len = test_env.reset(), False, 0, 0
while not (d or (ep_len == max_ep_len)):
# Take deterministic actions at test time
o, r, d, _ = test_env.step(get_action(o, True))
ep_ret += r
ep_len += 1
logger.store(TestEpRet=ep_ret, TestEpLen=ep_len)
start_time = time.time()
o, ep_ret, ep_len = env.reset(), 0, 0
total_steps = steps_per_epoch * epochs
# Main loop: collect experience in env and update/log each epoch
for t in range(total_steps):
# Until start_steps have elapsed, randomly sample actions
# from a uniform distribution for better exploration. Afterwards,
# use the learned policy.
if t > start_steps:
a = get_action(o)
else:
a = env.action_space.sample()
# Step the env
o2, r, d, _ = env.step(a)
ep_ret += r
ep_len += 1
# Ignore the "done" signal if it comes from hitting the time
# horizon (that is, when it's an artificial terminal signal
# that isn't based on the agent's state)
d = False if ep_len == max_ep_len else d
# Store experience to replay buffer
replay_buffer.store(o, a, r, o2, d)
# Super critical, easy to overlook step: make sure to update
# most recent observation!
o = o2
# End of trajectory handling
if d or (ep_len == max_ep_len):
logger.store(EpRet=ep_ret, EpLen=ep_len)
o, ep_ret, ep_len = env.reset(), 0, 0
# Update handling
if t >= update_after and t % update_every == 0:
for j in range(update_every):
batch = replay_buffer.sample_batch(batch_size)
feed_dict = {
x_ph: batch['obs1'],
x2_ph: batch['obs2'],
a_ph: batch['acts'],
r_ph: batch['rews'],
d_ph: batch['done'],
}
outs = sess.run(step_ops, feed_dict)
logger.store(LossPi=outs[0],
LossQ1=outs[1],
LossQ2=outs[2],
Q1Vals=outs[3],
Q2Vals=outs[4],
LogPi=outs[5])
# End of epoch wrap-up
if (t + 1) % steps_per_epoch == 0:
epoch = (t + 1) // steps_per_epoch
# Save model
if (epoch % save_freq == 0) or (epoch == epochs):
logger.save_state({'env': env}, None)
# Test the performance of the deterministic version of the agent.
test_agent()
# Log info about epoch
logger.log_tabular('Epoch', epoch)
logger.log_tabular('EpRet', with_min_and_max=True)
logger.log_tabular('TestEpRet', with_min_and_max=True)
logger.log_tabular('EpLen', average_only=True)
logger.log_tabular('TestEpLen', average_only=True)
logger.log_tabular('TotalEnvInteracts', t)
logger.log_tabular('Q1Vals', with_min_and_max=True)
logger.log_tabular('Q2Vals', with_min_and_max=True)
logger.log_tabular('LogPi', with_min_and_max=True)
logger.log_tabular('LossPi', average_only=True)
logger.log_tabular('LossQ1', average_only=True)
logger.log_tabular('LossQ2', average_only=True)
logger.log_tabular('Time', time.time() - start_time)
logger.dump_tabular()