def reset(self, output_dir):
"""Reset the model parameters.
Restores the parameters from the given output_dir if a checkpoint exists,
otherwise randomly initializes them.
Does not re-jit the model.
Args:
output_dir: Output directory.
"""
self._output_dir = output_dir
gfile.makedirs(output_dir)
# Create summary writers and history.
self._train_sw = jaxboard.SummaryWriter(
os.path.join(output_dir, "train"))
self._eval_sw = jaxboard.SummaryWriter(os.path.join(
output_dir, "eval"))
# Reset the train and eval streams.
self._train_stream = self._inputs.train_stream()
# TODO(lukaszkaiser): add an option to evaluate exactly on the full eval
# set by adding a padding and stopping the stream when too large.
self._eval_stream = _repeat_stream(self._inputs.eval_stream)
self._train_eval_stream = _repeat_stream(
self._inputs.train_eval_stream)
# Restore the training state.
state = restore_state(output_dir)
self._step = state.step or 0
history = state.history
self._lr_fn = self._lr_schedule(history)
self._history = history
if state.opt_state:
opt_state = state.opt_state
model_state = state.model_state
else:
opt_state, model_state = self._initialize()
model_state = layers.nested_map(model_state, self._maybe_replicate)
self._opt_state = OptState(
*layers.nested_map(opt_state, self._maybe_replicate))
self._model_state = model_state
if not state.opt_state:
self._maybe_save_state(keep=False)
self.update_optimizer_params()
def __init__(
self,
train_env,
eval_env,
output_dir,
policy_trainer_class,
n_real_epochs=10,
data_eval_frac=0.125,
model_train_batch_size=64,
n_model_train_steps=1000,
simulated_env_problem_class=(
simulated_env_problem.SerializedSequenceSimulatedEnvProblem),
simulated_batch_size=16,
n_simulated_epochs=1000,
trajectory_dump_dir=None,
initial_trajectory_dir=None,
initial_trajectory_mix_prob=0.5,
**kwargs):
super(SimPLe, self).__init__(train_env, eval_env, output_dir, **kwargs)
self._policy_dir = os.path.join(output_dir, "policy")
self._policy_trainer = policy_trainer_class(
train_env=train_env,
eval_env=eval_env,
output_dir=self._policy_dir,
async_mode=self._async_mode,
async_mode_trajectory_subdir=self._async_mode_trajectory_subdir,
)
self._n_real_epochs = n_real_epochs
self._model_train_batch_size = model_train_batch_size
self._n_model_train_steps = n_model_train_steps
self._data_eval_frac = data_eval_frac
self._model_dir = os.path.join(output_dir, "model")
self._sim_env = simulated_env_problem_class(
batch_size=None,
observation_space=train_env.observation_space,
action_space=train_env.action_space,
reward_range=train_env.reward_range,
discrete_rewards=train_env.discrete_rewards,
history_stream=None, # TODO(pkozakowski): Support this.
output_dir=self._model_dir,
)
self._simulated_batch_size = simulated_batch_size
self._n_simulated_epochs = n_simulated_epochs
# If trajectory_dump_dir is not provided explicitly, save the trajectories
# in output_dir.
if trajectory_dump_dir is None:
trajectory_dump_dir = os.path.join(output_dir, "trajectories")
self._trajectory_dump_root_dir = trajectory_dump_dir
self._initial_trajectory_dir = initial_trajectory_dir
self._initial_trajectory_mix_prob = initial_trajectory_mix_prob
self._summary_writer = jaxboard.SummaryWriter(self._output_dir)
self._simple_epoch = 0
self._policy_epoch = 0
self._model_train_step = 0
def reset(self, output_dir):
"""Reset the model parameters.
Restores the parameters from the given output_dir if a checkpoint exists,
otherwise randomly initializes them.
Does not re-jit the model.
Args:
output_dir: Output directory.
"""
self._output_dir = output_dir
gfile.makedirs(output_dir)
# Create summary writers and history.
self._train_sw = jaxboard.SummaryWriter(
os.path.join(output_dir, "train"))
self._eval_sw = jaxboard.SummaryWriter(os.path.join(
output_dir, "eval"))
# Reset the training stream.
self._train_stream = self._inputs.train_stream()
# Restore the training state.
state = restore_state(output_dir)
self._step = state.step or 0
history = state.history
self._lr_fn = self._lr_schedule(history)
self._history = history
if state.opt_state:
opt_state = state.opt_state
model_state = state.model_state
else:
opt_state, model_state = self._initialize()
model_state = layers.nested_map(model_state, self._maybe_replicate)
self._opt_state = OptState(
*layers.nested_map(opt_state, self._maybe_replicate))
self._model_state = model_state
if not state.opt_state:
self._maybe_save_state(keep=False)
self.update_learning_rate()
def __init__(self,
train_env,
eval_env,
output_dir,
policy_and_value_model=trax_models.FrameStackMLP,
policy_and_value_optimizer=functools.partial(
trax_opt.Adam, learning_rate=1e-3),
policy_and_value_two_towers=False,
n_optimizer_steps=N_OPTIMIZER_STEPS,
print_every_optimizer_steps=PRINT_EVERY_OPTIMIZER_STEP,
target_kl=0.01,
boundary=20,
max_timestep=None,
max_timestep_eval=20000,
random_seed=None,
gamma=GAMMA,
lambda_=LAMBDA,
c1=1.0,
c2=0.01,
eval_every_n=1000,
done_frac_for_policy_save=0.5,
n_evals=1,
len_history_for_policy=4,
eval_temperatures=(1.0, 0.5),
**kwargs):
"""Creates the PPO trainer.
Args:
train_env: gym.Env to use for training.
eval_env: gym.Env to use for evaluation.
output_dir: Output dir.
policy_and_value_model: Function defining the policy and value network,
without the policy and value heads.
policy_and_value_optimizer: Function defining the optimizer.
policy_and_value_two_towers: Whether to use two separate models as the
policy and value networks. If False, share their parameters.
n_optimizer_steps: Number of optimizer steps.
print_every_optimizer_steps: How often to log during the policy
optimization process.
target_kl: Policy iteration early stopping. Set to infinity to disable
early stopping.
boundary: We pad trajectories at integer multiples of this number.
max_timestep: If set to an integer, maximum number of time-steps in
a trajectory. Used in the collect procedure.
max_timestep_eval: If set to an integer, maximum number of time-steps in
an evaluation trajectory. Used in the collect procedure.
random_seed: Random seed.
gamma: Reward discount factor.
lambda_: N-step TD-error discount factor in GAE.
c1: Value loss coefficient.
c2: Entropy loss coefficient.
eval_every_n: How frequently to eval the policy.
done_frac_for_policy_save: Fraction of the trajectories that should be
done to checkpoint the policy.
n_evals: Number of times to evaluate.
len_history_for_policy: How much of history to give to the policy.
eval_temperatures: Sequence of temperatures to try for categorical
sampling during evaluation.
**kwargs: Additional keyword arguments passed to the base class.
"""
# Set in base class constructor.
self._train_env = None
self._should_reset = None
super(PPO, self).__init__(train_env, eval_env, output_dir, **kwargs)
self._n_optimizer_steps = n_optimizer_steps
self._print_every_optimizer_steps = print_every_optimizer_steps
self._target_kl = target_kl
self._boundary = boundary
self._max_timestep = max_timestep
self._max_timestep_eval = max_timestep_eval
self._gamma = gamma
self._lambda_ = lambda_
self._c1 = c1
self._c2 = c2
self._eval_every_n = eval_every_n
self._done_frac_for_policy_save = done_frac_for_policy_save
self._n_evals = n_evals
self._len_history_for_policy = len_history_for_policy
self._eval_temperatures = eval_temperatures
assert isinstance(self.train_env.action_space, gym.spaces.Discrete)
n_actions = self.train_env.action_space.n
# Batch Observations Shape = [1, 1] + OBS, because we will eventually call
# policy and value networks on shape [B, T] +_OBS
batch_observations_shape = (1,
1) + self.train_env.observation_space.shape
observations_dtype = self.train_env.observation_space.dtype
self._rng = trax.get_random_number_generator_and_set_seed(random_seed)
self._rng, key1 = jax_random.split(self._rng, num=2)
# Initialize the policy and value network.
policy_and_value_net_params, self._model_state, policy_and_value_net_apply = (
ppo.policy_and_value_net(
rng_key=key1,
batch_observations_shape=batch_observations_shape,
observations_dtype=observations_dtype,
n_actions=n_actions,
bottom_layers_fn=policy_and_value_model,
two_towers=policy_and_value_two_towers,
))
self._policy_and_value_net_apply = jit(policy_and_value_net_apply)
# Initialize the optimizer.
(policy_and_value_opt_state, self._policy_and_value_opt_update,
self._policy_and_value_get_params) = ppo.optimizer_fn(
policy_and_value_optimizer, policy_and_value_net_params)
# Maybe restore the optimization state. If there is nothing to restore, then
# iteration = 0 and policy_and_value_opt_state is returned as is.
(restored, self._policy_and_value_opt_state, self._model_state,
self._epoch, self._total_opt_step) = ppo.maybe_restore_opt_state(
output_dir, policy_and_value_opt_state, self._model_state)
if restored:
logging.info("Restored parameters from iteration [%d]",
self._epoch)
# We should start from the next iteration.
self._epoch += 1
# Create summary writers and history.
self._train_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "train"))
self._timing_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "timing"))
self._eval_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "eval"))
self._n_trajectories_done = 0
self._last_saved_at = 0
def __init__(self,
train_env,
eval_env,
output_dir,
policy_and_value_model=trax_models.FrameStackMLP,
policy_and_value_optimizer=functools.partial(
trax_opt.Adam, learning_rate=1e-3),
policy_and_value_two_towers=False,
policy_and_value_vocab_size=None,
n_optimizer_steps=N_OPTIMIZER_STEPS,
optimizer_batch_size=64,
print_every_optimizer_steps=PRINT_EVERY_OPTIMIZER_STEP,
target_kl=0.01,
boundary=20,
max_timestep=100,
max_timestep_eval=20000,
random_seed=None,
gamma=GAMMA,
lambda_=LAMBDA,
c1=1.0,
c2=0.01,
eval_every_n=1000,
save_every_n=1000,
done_frac_for_policy_save=0.5,
n_evals=1,
len_history_for_policy=4,
eval_temperatures=(1.0, 0.5),
separate_eval=True,
init_policy_from_world_model_output_dir=None,
**kwargs):
"""Creates the PPO trainer.
Args:
train_env: gym.Env to use for training.
eval_env: gym.Env to use for evaluation.
output_dir: Output dir.
policy_and_value_model: Function defining the policy and value network,
without the policy and value heads.
policy_and_value_optimizer: Function defining the optimizer.
policy_and_value_two_towers: Whether to use two separate models as the
policy and value networks. If False, share their parameters.
policy_and_value_vocab_size: Vocabulary size of a policy and value network
operating on serialized representation. If None, use raw continuous
representation.
n_optimizer_steps: Number of optimizer steps.
optimizer_batch_size: Batch size of an optimizer step.
print_every_optimizer_steps: How often to log during the policy
optimization process.
target_kl: Policy iteration early stopping. Set to infinity to disable
early stopping.
boundary: We pad trajectories at integer multiples of this number.
max_timestep: If set to an integer, maximum number of time-steps in a
trajectory. Used in the collect procedure.
max_timestep_eval: If set to an integer, maximum number of time-steps in
an evaluation trajectory. Used in the collect procedure.
random_seed: Random seed.
gamma: Reward discount factor.
lambda_: N-step TD-error discount factor in GAE.
c1: Value loss coefficient.
c2: Entropy loss coefficient.
eval_every_n: How frequently to eval the policy.
save_every_n: How frequently to save the policy.
done_frac_for_policy_save: Fraction of the trajectories that should be
done to checkpoint the policy.
n_evals: Number of times to evaluate.
len_history_for_policy: How much of history to give to the policy.
eval_temperatures: Sequence of temperatures to try for categorical
sampling during evaluation.
separate_eval: Whether to run separate evaluation using a set of
temperatures. If False, the training reward is reported as evaluation
reward with temperature 1.0.
init_policy_from_world_model_output_dir: Model output dir for initializing
the policy. If None, initialize randomly.
**kwargs: Additional keyword arguments passed to the base class.
"""
# Set in base class constructor.
self._train_env = None
self._should_reset = None
super(PPO, self).__init__(train_env, eval_env, output_dir, **kwargs)
self._n_optimizer_steps = n_optimizer_steps
self._optimizer_batch_size = optimizer_batch_size
self._print_every_optimizer_steps = print_every_optimizer_steps
self._target_kl = target_kl
self._boundary = boundary
self._max_timestep = max_timestep
self._max_timestep_eval = max_timestep_eval
self._gamma = gamma
self._lambda_ = lambda_
self._c1 = c1
self._c2 = c2
self._eval_every_n = eval_every_n
self._save_every_n = save_every_n
self._done_frac_for_policy_save = done_frac_for_policy_save
self._n_evals = n_evals
self._len_history_for_policy = len_history_for_policy
self._eval_temperatures = eval_temperatures
self._separate_eval = separate_eval
action_space = self.train_env.action_space
assert isinstance(action_space,
(gym.spaces.Discrete, gym.spaces.MultiDiscrete))
if isinstance(action_space, gym.spaces.Discrete):
n_actions = action_space.n
n_controls = 1
else:
(n_controls, ) = action_space.nvec.shape
assert n_controls > 0
assert onp.min(action_space.nvec) == onp.max(action_space.nvec), (
"Every control must have the same number of actions.")
n_actions = action_space.nvec[0]
self._n_actions = n_actions
self._n_controls = n_controls
self._rng = trax.get_random_number_generator_and_set_seed(random_seed)
self._rng, key1 = jax_random.split(self._rng, num=2)
vocab_size = policy_and_value_vocab_size
self._serialized_sequence_policy = vocab_size is not None
if self._serialized_sequence_policy:
self._serialization_kwargs = self._init_serialization(vocab_size)
else:
self._serialization_kwargs = {}
# Initialize the policy and value network.
policy_and_value_net = ppo.policy_and_value_net(
n_actions=n_actions,
n_controls=n_controls,
vocab_size=vocab_size,
bottom_layers_fn=policy_and_value_model,
two_towers=policy_and_value_two_towers,
)
self._policy_and_value_net_apply = jit(policy_and_value_net)
(batch_obs_shape, obs_dtype) = self._batch_obs_shape_and_dtype
policy_and_value_net_params, self._model_state = (
policy_and_value_net.initialize_once(batch_obs_shape, obs_dtype,
key1))
if init_policy_from_world_model_output_dir is not None:
policy_and_value_net_params = ppo.init_policy_from_world_model_checkpoint(
policy_and_value_net_params,
init_policy_from_world_model_output_dir)
# Initialize the optimizer.
(policy_and_value_opt_state, self._policy_and_value_opt_update,
self._policy_and_value_get_params) = ppo.optimizer_fn(
policy_and_value_optimizer, policy_and_value_net_params)
# Restore the optimizer state.
self._policy_and_value_opt_state = policy_and_value_opt_state
self._epoch = 0
self._total_opt_step = 0
self.update_optimization_state(
output_dir, policy_and_value_opt_state=policy_and_value_opt_state)
# Create summary writers and history.
self._train_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "train"))
self._timing_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "timing"))
self._eval_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "eval"))
self._n_trajectories_done = 0
self._last_saved_at = 0
if self._async_mode:
logging.info(
"Saving model on startup to have a model policy file.")
self.save()
self._rewards_to_actions = self._init_rewards_to_actions()
def training_loop(
env=None,
epochs=EPOCHS,
policy_and_value_net_fn=None,
policy_and_value_optimizer_fn=None,
batch_size=BATCH_TRAJECTORIES,
n_optimizer_steps=N_OPTIMIZER_STEPS,
print_every_optimizer_steps=PRINT_EVERY_OPTIMIZER_STEP,
target_kl=0.01,
boundary=20,
max_timestep=None,
max_timestep_eval=20000,
random_seed=None,
gamma=GAMMA,
lambda_=LAMBDA,
epsilon=EPSILON,
c1=1.0,
c2=0.01,
output_dir=None,
eval_every_n=1000,
eval_env=None,
done_frac_for_policy_save=0.5,
enable_early_stopping=True,
env_name=None,
n_evals=1,
len_history_for_policy=4,
):
"""Runs the training loop for PPO, with fixed policy and value nets."""
assert env
assert output_dir
assert env_name
gfile.makedirs(output_dir)
# Create summary writers and history.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
timing_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "timing"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
train_sw.text("env_name", env_name)
timing_sw.text("env_name", env_name)
eval_sw.text("env_name", env_name)
jax_rng_key = trax.get_random_number_generator_and_set_seed(random_seed)
# Batch Observations Shape = [1, 1] + OBS, because we will eventually call
# policy and value networks on shape [B, T] +_OBS
batch_observations_shape = (1, 1) + env.observation_space.shape
observations_dtype = env.observation_space.dtype
assert isinstance(env.action_space, gym.spaces.Discrete)
n_actions = env.action_space.n
jax_rng_key, key1 = jax_random.split(jax_rng_key, num=2)
# Initialize the policy and value network.
policy_and_value_net_params, policy_and_value_net_apply = (
policy_and_value_net_fn(key1, batch_observations_shape,
observations_dtype, n_actions))
# Maybe restore the policy params. If there is nothing to restore, then
# iteration = 0 and policy_and_value_net_params are returned as is.
restore, policy_and_value_net_params, iteration = (maybe_restore_params(
output_dir, policy_and_value_net_params))
if restore:
logging.info("Restored parameters from iteration [%d]", iteration)
# We should start from the next iteration.
iteration += 1
policy_and_value_net_apply = jit(policy_and_value_net_apply)
# Initialize the optimizers.
policy_and_value_optimizer = (
policy_and_value_optimizer_fn(policy_and_value_net_params))
(policy_and_value_opt_state, policy_and_value_opt_update,
policy_and_value_get_params) = policy_and_value_optimizer
n_trajectories_done = 0
last_saved_at = 0
logging.info("Starting the PPO training loop.")
for i in range(iteration, epochs):
epoch_start_time = time.time()
# Params we'll use to collect the trajectories.
policy_and_value_net_params = policy_and_value_get_params(
policy_and_value_opt_state)
# A function to get the policy and value predictions.
def get_predictions(observations, rng=None):
"""Returns log-probs, value predictions and key back."""
key, key1 = jax_random.split(rng, num=2)
log_probs, value_preds = policy_and_value_net_apply(
observations, policy_and_value_net_params, rng=key1)
return log_probs, value_preds, key
# Evaluate the policy.
policy_eval_start_time = time.time()
if ((i + 1) % eval_every_n == 0) or (i == epochs - 1):
jax_rng_key, key = jax_random.split(jax_rng_key, num=2)
logging.vlog(1, "Epoch [% 6d] evaluating policy.", i)
avg_reward, avg_reward_unclipped = evaluate_policy(
eval_env,
get_predictions,
max_timestep=max_timestep_eval,
n_evals=n_evals,
len_history_for_policy=len_history_for_policy,
rng=key)
for k, v in avg_reward.items():
eval_sw.scalar("eval/mean_reward/%s" % k, v, step=i)
logging.info(
"Epoch [% 6d] Policy Evaluation (clipped) [%s] = %10.2f",
i, k, v)
for k, v in avg_reward_unclipped.items():
eval_sw.scalar("eval/mean_reward_unclipped/%s" % k, v, step=i)
logging.info(
"Epoch [% 6d] Policy Evaluation (unclipped) [%s] = %10.2f",
i, k, v)
policy_eval_time = get_time(policy_eval_start_time)
trajectory_collection_start_time = time.time()
logging.vlog(1, "Epoch [% 6d] collecting trajectories.", i)
jax_rng_key, key = jax_random.split(jax_rng_key)
trajs, n_done, timing_info = collect_trajectories(
env,
policy_fn=get_predictions,
n_trajectories=batch_size,
max_timestep=max_timestep,
rng=key,
len_history_for_policy=len_history_for_policy,
reset=(i == 0) or restore,
epsilon=(10.0 / (i + 10.0))) # this is a different epsilon.
trajectory_collection_time = get_time(trajectory_collection_start_time)
logging.vlog(1, "Collecting trajectories took %0.2f msec.",
trajectory_collection_time)
avg_reward = float(sum(np.sum(traj[2]) for traj in trajs)) / len(trajs)
max_reward = max(np.sum(traj[2]) for traj in trajs)
min_reward = min(np.sum(traj[2]) for traj in trajs)
train_sw.scalar("train/mean_reward", avg_reward, step=i)
logging.vlog(1,
"Rewards avg=[%0.2f], max=[%0.2f], min=[%0.2f], all=%s",
avg_reward, max_reward, min_reward,
[float(np.sum(traj[2])) for traj in trajs])
logging.vlog(
1, "Trajectory Length average=[%0.2f], max=[%0.2f], min=[%0.2f]",
float(sum(len(traj[0]) for traj in trajs)) / len(trajs),
max(len(traj[0]) for traj in trajs),
min(len(traj[0]) for traj in trajs))
logging.vlog(2, "Trajectory Lengths: %s",
[len(traj[0]) for traj in trajs])
padding_start_time = time.time()
(_, reward_mask, padded_observations, padded_actions,
padded_rewards) = pad_trajectories(trajs, boundary=boundary)
padding_time = get_time(padding_start_time)
logging.vlog(1, "Padding trajectories took %0.2f msec.",
get_time(padding_start_time))
logging.vlog(1, "Padded Observations' shape [%s]",
str(padded_observations.shape))
logging.vlog(1, "Padded Actions' shape [%s]",
str(padded_actions.shape))
logging.vlog(1, "Padded Rewards' shape [%s]",
str(padded_rewards.shape))
# Calculate log-probabilities and value predictions of the trajectories.
# We'll pass these to the loss functions so as to not get recomputed.
# NOTE:
# There is a slight problem here, if the policy network contains
# stochasticity in the log-probabilities (ex: dropout), then calculating
# these again here is not going to be correct and should be done in the
# collect function.
log_prob_recompute_start_time = time.time()
jax_rng_key, key = jax_random.split(jax_rng_key)
log_probabs_traj, value_predictions_traj, _ = get_predictions(
padded_observations, rng=key)
log_prob_recompute_time = get_time(log_prob_recompute_start_time)
# Some assertions.
B, T = padded_actions.shape # pylint: disable=invalid-name
assert (B, T) == padded_rewards.shape
assert (B, T) == reward_mask.shape
assert (B, T + 1) == padded_observations.shape[:2]
assert (B, T +
1) + env.observation_space.shape == padded_observations.shape
# Linear annealing from 0.1 to 0.0
# epsilon_schedule = epsilon if epochs == 1 else epsilon * (1.0 -
# (i /
# (epochs - 1)))
# Constant epsilon.
epsilon_schedule = epsilon
# Compute value and ppo losses.
jax_rng_key, key1 = jax_random.split(jax_rng_key, num=2)
logging.vlog(2, "Starting to compute P&V loss.")
loss_compute_start_time = time.time()
cur_combined_loss, cur_ppo_loss, cur_value_loss, entropy_bonus = (
combined_loss(policy_and_value_net_params,
log_probabs_traj,
value_predictions_traj,
policy_and_value_net_apply,
padded_observations,
padded_actions,
padded_rewards,
reward_mask,
gamma=gamma,
lambda_=lambda_,
epsilon=epsilon_schedule,
c1=c1,
c2=c2,
rng=key1))
loss_compute_time = get_time(loss_compute_start_time)
logging.vlog(
1,
"Calculating P&V loss [%10.2f(%10.2f, %10.2f, %10.2f)] took %0.2f msec.",
cur_combined_loss, cur_value_loss, cur_ppo_loss, entropy_bonus,
get_time(loss_compute_start_time))
jax_rng_key, key1 = jax_random.split(jax_rng_key, num=2)
logging.vlog(1, "Policy and Value Optimization")
optimization_start_time = time.time()
keys = jax_random.split(key1, num=n_optimizer_steps)
for j in range(n_optimizer_steps):
k1, k2, k3 = jax_random.split(keys[j], num=3)
t = time.time()
# Update the optimizer state.
policy_and_value_opt_state = policy_and_value_opt_step(
j,
policy_and_value_opt_state,
policy_and_value_opt_update,
policy_and_value_get_params,
policy_and_value_net_apply,
log_probabs_traj,
value_predictions_traj,
padded_observations,
padded_actions,
padded_rewards,
reward_mask,
c1=c1,
c2=c2,
gamma=gamma,
lambda_=lambda_,
epsilon=epsilon_schedule,
rng=k1)
# Compute the approx KL for early stopping.
new_policy_and_value_net_params = policy_and_value_get_params(
policy_and_value_opt_state)
log_probab_actions_new, _ = policy_and_value_net_apply(
padded_observations, new_policy_and_value_net_params, rng=k2)
approx_kl = approximate_kl(log_probab_actions_new,
log_probabs_traj, reward_mask)
early_stopping = enable_early_stopping and approx_kl > 1.5 * target_kl
if early_stopping:
logging.vlog(
1,
"Early stopping policy and value optimization at iter: %d, "
"with approx_kl: %0.2f", j, approx_kl)
# We don't return right-away, we want the below to execute on the last
# iteration.
t2 = time.time()
if (((j + 1) % print_every_optimizer_steps == 0)
or (j == n_optimizer_steps - 1) or early_stopping):
# Compute and log the loss.
(loss_combined, loss_ppo, loss_value,
entropy_bonus) = (combined_loss(
new_policy_and_value_net_params,
log_probabs_traj,
value_predictions_traj,
policy_and_value_net_apply,
padded_observations,
padded_actions,
padded_rewards,
reward_mask,
gamma=gamma,
lambda_=lambda_,
epsilon=epsilon_schedule,
c1=c1,
c2=c2,
rng=k3))
logging.vlog(
1, "One Policy and Value grad desc took: %0.2f msec",
get_time(t, t2))
logging.vlog(
1, "Combined Loss(value, ppo, entropy_bonus) [%10.2f] ->"
" [%10.2f(%10.2f,%10.2f,%10.2f)]", cur_combined_loss,
loss_combined, loss_value, loss_ppo, entropy_bonus)
if early_stopping:
break
optimization_time = get_time(optimization_start_time)
logging.vlog(
1, "Total Combined Loss reduction [%0.2f]%%",
(100 *
(cur_combined_loss - loss_combined) / np.abs(cur_combined_loss)))
# Save parameters every time we see the end of at least a fraction of batch
# number of trajectories that are done (not completed -- completed includes
# truncated and done).
# Also don't save too frequently, enforce a minimum gap.
# Or if this is the last iteration.
policy_save_start_time = time.time()
n_trajectories_done += n_done
# TODO(afrozm): Refactor to trax.save_state.
if (((n_trajectories_done >= done_frac_for_policy_save * batch_size)
and (i - last_saved_at > eval_every_n) and
(((i + 1) % eval_every_n == 0))) or (i == epochs - 1)):
logging.vlog(1, "Epoch [% 6d] saving model.", i)
old_model_files = gfile.glob(
os.path.join(output_dir, "model-??????.pkl"))
params_file = os.path.join(output_dir, "model-%06d.pkl" % i)
with gfile.GFile(params_file, "wb") as f:
pickle.dump(policy_and_value_net_params, f)
# Remove the old model files.
for path in old_model_files:
gfile.remove(path)
# Reset this number.
n_trajectories_done = 0
last_saved_at = i
policy_save_time = get_time(policy_save_start_time)
epoch_time = get_time(epoch_start_time)
logging.info(
"Epoch [% 6d], Reward[min, max, avg] [%5.2f,%5.2f,%5.2f], Combined"
" Loss(value, ppo, entropy) [%2.5f(%2.5f,%2.5f,%2.5f)]", i,
min_reward, max_reward, avg_reward, loss_combined, loss_value,
loss_ppo, entropy_bonus)
timing_dict = {
"epoch": epoch_time,
"policy_eval": policy_eval_time,
"trajectory_collection": trajectory_collection_time,
"padding": padding_time,
"log_prob_recompute": log_prob_recompute_time,
"loss_compute": loss_compute_time,
"optimization": optimization_time,
"policy_save": policy_save_time,
}
timing_dict.update(timing_info)
for k, v in timing_dict.items():
timing_sw.scalar("timing/%s" % k, v, step=i)
max_key_len = max(len(k) for k in timing_dict)
timing_info_list = [
"%s : % 10.2f" % (k.rjust(max_key_len + 1), v)
for k, v in sorted(timing_dict.items())
]
logging.info("Epoch [% 6d], Timings: \n%s", i,
"\n".join(timing_info_list))
# Reset restore.
restore = False
# Flush summary writers once in a while.
if (i + 1) % 1000 == 0 or i == epochs - 1:
train_sw.flush()
timing_sw.flush()
eval_sw.flush()
def __init__(self, model, loss_fn, optimizer, lr_schedule, inputs, output_dir,
random_seed=None, n_devices=None, save_steps=None):
if save_steps is None:
save_steps = []
self._save_steps = save_steps
device_count = jax.lib.xla_bridge.device_count()
n_devices = n_devices or device_count
# TODO(lukaszkaiser): remove this restriction when possible.
if n_devices != device_count:
raise ValueError("Jax cannot work yet with n_devices != all devices: "
"%d != %d" % (n_devices, device_count))
self._n_devices = n_devices
rng = get_random_number_generator_and_set_seed(random_seed)
self._output_dir = output_dir
gfile.makedirs(output_dir)
# Create summary writers and history.
self._train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
self._eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
# Create input streams.
inputs = inputs(n_devices)
self._inputs = inputs
self._train_stream = inputs.train_stream()
# Setup optimizer and model.
state = restore_state(output_dir)
history = state.history
self._lr_fn = lr_schedule(history)
opt = optimizer(self._lr_fn)
model_train = model(mode="train")
model_predict_eval = model(mode="eval")
# Setup state.
step = state.step or 0
rng, init_rng = jax_random.split(rng)
self._rngs = jax_random.split(rng, n_devices)
first_shape = inputs.input_shape[0]
# If the inputs are a tuple/list, add [None] (batch) to each element.
if isinstance(first_shape, (list, tuple)):
model_input_shape = tuple(
tuple([None] + list(shape)) for shape in inputs.input_shape)
else: # Otherwise just add [None] to the input shape.
model_input_shape = tuple([None] + list(inputs.input_shape))
# Change all None to 1 in input shape.
model_input_shape = layers.nested_map(
model_input_shape, lambda x: x if x else 1)
if state.params:
params = state.params[0]
opt_state = state.params
else:
params = model_train.initialize(
model_input_shape, inputs.input_dtype, init_rng)
opt_state = (params, opt.tree_init(params))
if n_devices > 1:
replicate = lambda x: numpy.broadcast_to(x, (n_devices,) + x.shape)
opt_state = layers.nested_map(opt_state, replicate)
# jit model_predict and update so they're fast
self._jit_model_predict_eval = _jit_predict_fn(
model_predict_eval, n_devices)
self._jit_update_fn = _jit_update_fn(model_train, loss_fn, opt, n_devices)
self._step = step
self._model_train = model_train
self._model_predict_eval = model_predict_eval
self._loss_fn = loss_fn
self._optimizer = optimizer
self._opt_state = opt_state
self._history = history
self._lr_schedule = lr_schedule
def train(output_dir,
model=gin.REQUIRED,
loss_fn=loss,
inputs=trax_inputs.inputs,
optimizer=trax_opt.SM3,
lr_schedule=lr.MultifactorSchedule,
train_steps=1000,
save_steps=None,
eval_steps=10,
eval_frequency=100,
n_devices=None,
random_seed=None,
run_debug_step=False,
save_graphs=True,
save_backward_graph=False):
"""Train the model on the inputs.
Args:
output_dir: Directory where to put the logs and checkpoints.
model: The model to train as a callable returning 2 callables, an init_fn
and apply_fn.
loss_fn: callable with signature: params, trax.inputs.Inputs, model, rng
-> loss.
inputs: callable returning trax.inputs.Inputs.
optimizer: The optimizer (see optimizers/base.py for signature).
lr_schedule: A learning rate schedule as a function that takes history and
returns a function from step to learning rate (a float).
train_steps: int, total number of training steps.
save_steps: list of integers. Keep a model file at each of the supplied save
steps.
eval_steps: int, num of steps per evaluation. If None or 0, eval disabled.
eval_frequency: int, how often to run evaluation (every eval_frequency
steps). If None or 0, eval disabled.
n_devices: how many devices to use (if None, default, use all available)
random_seed: the random seed to use; time/os dependent if None (default).
run_debug_step: bool, if True, will run the model and loss without @jit for
one step.
save_graphs: bool, if True, save computation graph to file.
save_backward_graph: bool, if True, save backward graph to file too.
Returns:
trax.State
"""
if save_steps is None:
save_steps = []
device_count = jax.lib.xla_bridge.device_count()
n_devices = n_devices or device_count
# TODO(lukaszkaiser): remove this restriction when possible.
if n_devices != device_count:
raise ValueError("Jax cannot work yet with n_devices != all devices: "
"%d != %d" % (n_devices, device_count))
rng = get_random_number_generator_and_set_seed(random_seed)
gfile.makedirs(output_dir)
# Create summary writers and history.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
inputs = inputs(n_devices)
# Setup optimizer and model
state = restore_state(output_dir)
history = state.history
lr_fn = lr_schedule(history)
opt = optimizer(lr_fn)
model_train = layers.Serial(model(mode="train"))
model_predict_eval = layers.Serial(model(mode="eval"))
# Setup state
step = state.step or 0
rng, init_rng = jax_random.split(rng)
rngs = jax_random.split(rng, n_devices)
first_shape = inputs.input_shape[0]
# If the inputs are a tuple/list, add [-1] (batch) to each element.
if isinstance(first_shape, (list, tuple)):
model_input_shape = tuple(
[tuple([-1] + list(shape)) for shape in inputs.input_shape])
else: # Otherwise just add [-1] to the input shape.
model_input_shape = tuple([-1] + list(inputs.input_shape))
if state.params:
params = state.params[0]
opt_state = state.params
else:
params = model_train.initialize(model_input_shape, init_rng)
opt_state = (params, opt.tree_init(params))
if n_devices > 1:
replicate = lambda x: numpy.broadcast_to(x, (n_devices,) + x.shape)
opt_state = layers.nested_map(opt_state, replicate)
# jit model_predict and update so they're fast
jit_model_predict_eval = _jit_predict_fn(model_predict_eval, n_devices)
jit_update_fn = _jit_update_fn(model_train, loss_fn, opt, n_devices)
train_stream = inputs.train_stream()
epoch_steps = [train_steps] # Only training if eval_frequency is 0 or None.
if eval_frequency and eval_steps > 0:
epoch_steps = itertools.chain([1, # first epoch only 1 step
eval_frequency - 1],
itertools.repeat(eval_frequency))
step_log(step, "Starting training using %d devices" % n_devices)
# Non-compiled debug step helps find problems in models easier.
if run_debug_step:
debug_loss = loss_fn(params, next(train_stream), model_train, rng)
step_log(step, "Debug step loss %.8f" % debug_loss)
for epoch, epoch_steps in epochs(train_steps, epoch_steps):
# Log separator
print()
# Timer
start_time = time.time()
for _ in range(epoch_steps):
# Train
next_train_batch = next(train_stream)
if n_devices > 1: # TODO(lukaszkaiser): use everywhere when possible.
next_train_batch = reshape_by_device(next_train_batch, n_devices)
opt_state, rngs = jit_update_fn(step, opt_state, next_train_batch, rngs)
step += 1
if step in save_steps:
_save_replicated(opt_state, step, history, n_devices, output_dir, True)
# LR log
if step == 1 or step % 10 == 0:
train_sw.scalar("training/learning rate",
lr_fn(step), step=step)
# Timer
epoch_time = time.time() - start_time
step_log(step, "Ran %d train steps in %0.2f secs" %
(epoch_steps, epoch_time))
if epoch_steps > 1:
train_sw.scalar("training/steps per second",
epoch_steps / epoch_time, step=step)
# Print number of parameters
if step == 1:
sizes = layers.sizes(opt_state[0])
if n_devices > 1:
unreplicate = lambda x: x.mean(0)
single_params = layers.nested_map(opt_state[0], unreplicate)
sizes = layers.sizes(single_params)
total_size = layers.nested_reduce(sizes, sum)
step_log(step, "Total trainable parameters size: %d" % total_size)
# Evaluate in parallel
evaluate_train_and_eval(
step=step,
inputs=inputs,
predict_fn=functools.partial(jit_model_predict_eval,
params=opt_state[0]),
eval_steps=eval_steps,
rng=rng,
train_sw=train_sw,
eval_sw=eval_sw,
history=history)
# Save computation graph (single-device only for now).
if save_graphs and step == 1 and n_devices == 1:
params = opt_state[0]
# Dump computation graphs to files.
forward_computation = jax.xla_computation(model_predict_eval)(
next_train_batch[0], params=params, rng=rng)
with gfile.GFile(os.path.join(output_dir, "forward.txt"), "w") as f:
f.write(forward_computation.GetHloText())
with gfile.GFile(os.path.join(output_dir, "forward.dot"), "w") as f:
f.write(forward_computation.GetHloDotGraph())
backward_computation = jax.xla_computation(jit_update_fn)(
step, opt_state, next_train_batch, rngs)
with gfile.GFile(os.path.join(output_dir, "backward.txt"), "w") as f:
f.write(backward_computation.GetHloText())
if save_backward_graph: # Backward graphs can be large so we guard it.
with gfile.GFile(os.path.join(output_dir, "backward.dot"), "w") as f:
f.write(backward_computation.GetHloDotGraph())
# Save state
_save_replicated(opt_state, step, history, n_devices, output_dir, False)
# Save Gin config
# Gin only tracks the used parameters, so we save it after the first epoch.
if epoch == 1:
save_gin(output_dir, train_sw)
# Update learning rate with new history
old_lr_fn = lr_fn
lr_fn = lr_schedule(history)
if lr_fn != old_lr_fn: # For performance, only jit if there is a change.
opt = optimizer(lr_fn)
jit_update_fn = _jit_update_fn(model_train, loss_fn, opt, n_devices)
# Flush summary writers
train_sw.flush()
eval_sw.flush()
step_log(step, "Training done")
return State(params=opt_state, step=step, history=history)
def train(output_dir,
model=gin.REQUIRED,
loss_fun=loss,
inputs=trax_inputs.inputs,
optimizer=trax_opt.adam,
lr_schedule=lr.MultifactorSchedule,
train_steps=1000,
eval_steps=10,
eval_frequency=100,
num_devices=None,
random_seed=None,
run_debug_step=False):
"""Train the model on the inputs.
Args:
output_dir: Directory where to put the logs and checkpoints.
model: The model to train as a callable returning 2 callables, an init_fun
and apply_fun.
loss_fun: callable with signature: params, trax.inputs.Inputs, model, rng
-> loss.
inputs: callable returning trax.inputs.Inputs.
optimizer: The optimizer as a callable taking a learning_rate callable and
returning 2 callables, opt_init and opt_update.
lr_schedule: A learning rate schedule as a function that takes history and
returns a function from step to learning rate (a float).
train_steps: int, total number of training steps.
eval_steps: int, num of steps per evaluation. If None or 0, eval disabled.
eval_frequency: int, how often to run evaluation (every eval_frequency
steps). If None or 0, eval disabled.
num_devices: how many devices to use (if None, default, use all available)
random_seed: the random seed to use; time/os dependent if None (default).
run_debug_step: bool, if True, will run the model and loss without @jit for
one step.
Returns:
trax.State
"""
num_devices = num_devices or jax.lib.xla_bridge.device_count()
rng = get_random_number_generator_and_set_seed(random_seed)
gfile.makedirs(output_dir)
# Create summary writers and history.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
inputs = inputs(num_devices)
# Setup optimizer and model
state = restore_state(output_dir)
history = state.history
lr_fun = lr_schedule(history)
opt_init, _ = optimizer(lr_fun)
model_init, model_predict_train = model(mode="train")
_, model_predict_eval = model(mode="eval")
# Setup state
step = state.step or 0
rng, init_key = jax_random.split(rng)
params_initializer = \
lambda: model_init(init_key, [-1] + list(inputs.input_shape))[1]
params = state.params or params_initializer()
opt_state = opt_init(params)
if num_devices > 1: # TODO(lukaszkaiser): use everywhere when pmap is stable.
opt_state = jax.replicate(opt_state)
# jit model_predict and update so they're fast
jit_model_predict_eval = _jit_predict_fun(model_predict_eval, num_devices)
jit_update_fun = _jit_update_fun(
model_predict_train, loss_fun, optimizer, lr_fun, num_devices)
print()
train_stream = inputs.train_stream()
epoch_steps = [train_steps] # Only training if eval_frequency is 0 or None.
if eval_frequency and eval_steps > 0:
epoch_steps = itertools.chain([1, # first epoch only 1 step
eval_frequency - 1],
itertools.repeat(eval_frequency))
step_log(step, "Starting training using %d devices" % num_devices)
# Non-compiled debug step helps find problems in models easier.
if run_debug_step:
debug_loss = loss_fun(params, next(train_stream), model_predict_train, rng)
step_log(step, "Debug step loss %.8f" % debug_loss)
for epoch, epoch_steps in epochs(train_steps, epoch_steps):
# Log separator
print()
# Timer
start_time = time.time()
for _ in range(epoch_steps):
# Train
next_train_batch = next(train_stream)
if num_devices > 1: # TODO(lukaszkaiser): use everywhere when possible.
next_train_batch = reshape_by_device_pair(next_train_batch, num_devices)
rng, subrng = jax_random.split(rng)
opt_state = jit_update_fun(step, opt_state, next_train_batch, subrng)
step += 1
# LR log
if step == 1 or step % 10 == 0:
train_sw.scalar("training/learning rate",
lr_fun(step), step=step)
# Timer
epoch_time = time.time() - start_time
step_log(step, "Ran %d train steps in %0.2f secs" %
(epoch_steps, epoch_time))
if epoch_steps > 1:
train_sw.scalar("training/steps per second",
epoch_steps / epoch_time, step=step)
# Evaluate
params = trax_opt.get_params(opt_state)
evaluate_train_and_eval(
step=step,
inputs=inputs,
predict_fun=functools.partial(jit_model_predict_eval, params),
eval_steps=eval_steps,
rng=rng,
train_sw=train_sw,
eval_sw=eval_sw,
history=history)
# Save state
save_state(State(params=params, step=step, history=history), output_dir)
# Save Gin config
# Gin only tracks the used parameters, so we save it after the first epoch.
if epoch == 1:
save_gin(output_dir, train_sw)
# Update learning rate with new history
old_lr_fun = lr_fun
lr_fun = lr_schedule(history)
if lr_fun != old_lr_fun: # For performance, only jit if there is a change.
jit_update_fun = _jit_update_fun(
model_predict_train, loss_fun, optimizer, lr_fun, num_devices)
# Flush summary writers
train_sw.flush()
eval_sw.flush()
step_log(step, "Training done")
return State(params=params, step=step, history=history)
def train(output_dir,
model=gin.REQUIRED,
inputs=gin.REQUIRED,
optimizer=trax_opt.adam,
lr_schedule=lr.MultifactorSchedule,
train_steps=1000,
eval_steps=10,
eval_frequency=100,
run_debug_step=False):
"""Train the model on the inputs.
Args:
output_dir: Directory where to put the logs and checkpoints.
model: The model to train as a callable returning 2 callables, an init_fun
and apply_fun.
inputs: callable returning trax.inputs.Inputs.
optimizer: The optimizer as a callable taking a learning_rate callable and
returning 2 callables, opt_init and opt_update.
lr_schedule: A learning rate schedule as a function that takes history and
returns a function from step to learning rate (a float).
train_steps: int, total number of training steps.
eval_steps: int, num of steps per evaluation. If None or 0, eval disabled.
eval_frequency: int, how often to run evaluation (every eval_frequency
steps). If None or 0, eval disabled.
run_debug_step: bool, if True, will run the model and loss without @jit for
one step.
Returns:
trax.State
"""
rng = random.PRNGKey(0)
gfile.makedirs(output_dir)
# Create summary writers and history.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
inputs = inputs()
# Setup optimizer and model
state = restore_state(output_dir)
history = state.history
lr_fun = lr_schedule(history)
opt_init, _ = optimizer(lr_fun)
model_init, model_predict_original = model()
# We need a model_predict that fills in the random generator if needed.
def model_predict(x, y, **kwargs):
"""Same as model_predict_original but fill in rng if it isn't passed."""
if "rng" in kwargs:
return model_predict_original(x, y, **kwargs)
return model_predict_original(x, y, rng=rng, **kwargs)
# Setup state
step = state.step or 0
params_initializer = lambda: model_init([-1] + list(inputs.input_shape))[1]
params = state.params or params_initializer()
opt_state = opt_init(params)
# jit model_predict and update so they're fast
jit_model_predict = jax.jit(model_predict) # for evaluation
jit_update_fun = _jit_update_fun(model_predict, loss, optimizer, lr_fun)
print()
train_stream = inputs.train_stream()
epoch_steps = itertools.chain(
[
1, # first epoch only 1 step
eval_frequency - 1
],
itertools.repeat(eval_frequency))
step_log(step, "Starting training")
# Non-compiled debug step helps find problems in models easier.
if run_debug_step:
debug_loss = loss(params, next(train_stream), model_predict)
step_log(step, "Debug step loss %.8f" % debug_loss)
for epoch, epoch_steps in epochs(train_steps, epoch_steps):
# Log separator
print()
# Timer
start_time = time.time()
for _ in range(epoch_steps):
# Train
opt_state = jit_update_fun(step, opt_state, next(train_stream))
step += 1
# LR log
if step == 1 or step % 10 == 0:
train_sw.scalar("training/learning rate",
lr_fun(step),
step=step)
# Timer
epoch_time = time.time() - start_time
step_log(
step,
"Ran %d train steps in %0.2f secs" % (epoch_steps, epoch_time))
if epoch_steps > 1:
train_sw.scalar("training/steps per second",
epoch_steps / epoch_time,
step=step)
# Evaluate
params = jax_opt.get_params(opt_state)
evaluate_train_and_eval(step=step,
inputs=inputs,
predict_fun=functools.partial(
jit_model_predict, params),
eval_steps=eval_steps,
train_sw=train_sw,
eval_sw=eval_sw,
history=history)
# Save state
save_state(State(params=params, step=step, history=history),
output_dir)
# Save Gin config
# Gin only tracks the used parameters, so we save it after the first epoch.
if epoch == 1:
save_gin(output_dir, train_sw)
# Update learning rate with new history
old_lr_fun = lr_fun
lr_fun = lr_schedule(history)
if lr_fun != old_lr_fun: # For performance, only jit if there is a change.
jit_update_fun = _jit_update_fun(model_predict, loss, optimizer,
lr_fun)
# Flush summary writers
train_sw.writer.flush()
eval_sw.writer.flush()
step_log(step, "Training done")
return State(params=params, step=step, history=history)
def train(output_dir,
model=gin.REQUIRED,
inputs=gin.REQUIRED,
optimizer=trax_opt.adam,
train_steps=1000,
eval_steps=10,
eval_frequency=100):
"""Train the model on the inputs.
Args:
output_dir: Directory where to put the logs and checkpoints.
model: The model to train as a callable returning 2 callables, an init_fun
and apply_fun.
inputs: callable returning trax.inputs.Inputs.
optimizer: The optimizer as a callable taking a learning_rate callable and
returning 2 callables, opt_init and opt_update.
train_steps: int, total number of training steps.
eval_steps: int, num of steps per evaluation. If None or 0, eval disabled.
eval_frequency: int, how often to run evaluation (every eval_frequency
steps). If None or 0, eval disabled.
Returns:
trax.State
"""
gfile.makedirs(output_dir)
inputs = inputs()
# Setup optimizer and model
opt_init, opt_update = optimizer(learning_rate)
model_init, model_predict = model()
# Setup state
state = restore_state(output_dir)
step = state.step or 0
params_initializer = lambda: model_init([-1] + inputs.input_shape)[1]
opt_state = opt_init(state.params or params_initializer())
# Create summary writers.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
# jit model_predict and update so they're fast
jit_predict = jax.jit(model_predict) # for evaluation
@jax.jit
def update(i, opt_state, batch):
params = jax_opt.get_params(opt_state)
return opt_update(i,
jax.grad(loss)(params, batch, model_predict),
opt_state)
print()
step_log(step, "starting training")
inputs_stream = inputs.train_fn()
eval_enabled = eval_steps and eval_frequency
is_first_step = True
# Evaluate after the first training step, then reset to normal_epoch_steps
normal_epoch_steps = (eval_enabled and eval_frequency) or train_steps
epoch_steps = 1
while step < train_steps:
print() # separate logging for each loop iteration
# Train
start_time = time.time()
for _ in range(epoch_steps):
opt_state = update(step, opt_state, next(inputs_stream))
if step % 10 == 0: # Log learning rate curve each 10 steps.
train_sw.scalar("training/learning rate",
learning_rate(step),
step=step)
step += 1
epoch_time = time.time() - start_time
step_log(
step,
"ran %d train steps in %0.2f secs" % (epoch_steps, epoch_time))
# Save state
params = jax_opt.get_params(opt_state)
save_state(State(params=params, step=step), output_dir)
# Evaluate
if eval_enabled:
step_log(step, "starting evaluation")
train_metrics, eval_metrics = evaluate(
inputs, functools.partial(jit_predict, params), eval_steps)
log_metrics(train_metrics, train_sw, "train", step)
log_metrics(eval_metrics, eval_sw, "eval ", step)
eval_sw.writer.flush()
# Gin only tracks the used parameters, so we save it after the first step.
if is_first_step:
save_gin(output_dir, train_sw)
# Log non-metric reports.
if not is_first_step:
train_sw.scalar("training/steps per second",
epoch_steps / epoch_time,
step=step)
train_sw.writer.flush()
# After the first step, train for normal_epoch_steps steps before evaluating
epoch_steps = ((normal_epoch_steps -
1) if is_first_step else normal_epoch_steps)
is_first_step = False
print()
step_log(step, "finished training")
return State(params=params, step=step)
def train(output_dir,
data_dir,
model=gin.REQUIRED,
dataset=gin.REQUIRED,
optimizer=trax_opt.adam,
train_steps=1000,
eval_steps=10,
eval_frequency=100):
"""Train the given model on the given dataset.
Args:
output_dir: Directory where to put the logs and checkpoints.
data_dir: Directory where the data is located.
model: The model to train as a callable returning 2 callables, an init_fun
and apply_fun.
dataset: The name of the TFDS dataset to train on. To train on a T2T
dataset, prefix the name with "t2t_".
optimizer: The optimizer as a callable taking a learning_rate callable and
returning 2 callables, opt_init and opt_update.
train_steps: int, total number of training steps.
eval_steps: int, num of steps per evaluation.
eval_frequency: int, how often to run evaluation (every eval_frequency
steps).
"""
gfile.makedirs(output_dir)
# Make Inputs
inputs = inputs_lib.make_inputs(dataset, data_dir)
# Setup optimizer and model
opt_init, opt_update = optimizer(learning_rate)
model_init, model_predict = model()
# Setup state
state = restore_state(output_dir)
step = state.step or 0
params_initializer = lambda: model_init([-1] + inputs.input_shape)[1]
opt_state = opt_init(state.params or params_initializer())
# Create summary writers.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
# jit model_predict and update so they're fast
jit_predict = jax.jit(model_predict) # for evaluation
@jax.jit
def update(i, opt_state, batch):
params = jax_opt.get_params(opt_state)
return opt_update(i, jax.grad(loss)(
params, batch, model_predict), opt_state)
print()
step_log(step, "starting training")
inputs_stream = inputs.train_fn()
is_first_step = True
epoch_steps = 1 # First evaluation after the first training step.
while step < train_steps:
print()
# Train
start_time = time.time()
for _ in range(epoch_steps):
opt_state = update(step, opt_state, next(inputs_stream))
if step % 10 == 0: # Log learning rate curve each 10 steps.
train_sw.scalar("training/learning rate",
learning_rate(step), step=step)
step += 1
epoch_time = time.time() - start_time
step_log(step, "ran %d train steps in %0.2f secs" %
(epoch_steps, epoch_time))
# Save state
params = jax_opt.get_params(opt_state)
save_state(State(params=params, step=step), output_dir,
save_gin=is_first_step)
# Evaluate
step_log(step, "starting evaluation")
train_metrics, eval_metrics = evaluate(
inputs, functools.partial(jit_predict, params), eval_steps)
log_metrics(train_metrics, train_sw, "train", step)
log_metrics(eval_metrics, eval_sw, "eval ", step)
# Log non-metric reports and flush.
if not is_first_step:
train_sw.scalar("training/steps per second",
epoch_steps / epoch_time, step=step)
train_sw.writer.flush()
eval_sw.writer.flush()
# After the first step, train for eval_frequency steps before evaluating
epoch_steps = (eval_frequency - 1) if is_first_step else eval_frequency
is_first_step = False
print()
step_log(step, "finished training")
def train(output_dir,
model=gin.REQUIRED,
inputs=gin.REQUIRED,
optimizer=trax_opt.adam,
lr_schedule=lr.MultifactorSchedule,
train_steps=1000,
eval_steps=10,
eval_frequency=100):
"""Train the model on the inputs.
Args:
output_dir: Directory where to put the logs and checkpoints.
model: The model to train as a callable returning 2 callables, an init_fun
and apply_fun.
inputs: callable returning trax.inputs.Inputs.
optimizer: The optimizer as a callable taking a learning_rate callable and
returning 2 callables, opt_init and opt_update.
lr_schedule: A learning rate schedule as a function that takes history and
returns a function from step to learning rate (a float).
train_steps: int, total number of training steps.
eval_steps: int, num of steps per evaluation. If None or 0, eval disabled.
eval_frequency: int, how often to run evaluation (every eval_frequency
steps). If None or 0, eval disabled.
Returns:
trax.State
"""
gfile.makedirs(output_dir)
# Create summary writers and history.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
inputs = inputs()
# Setup optimizer and model
state = restore_state(output_dir)
history = state.history
lr_fun = lr_schedule(history)
opt_init, opt_update = optimizer(lr_fun)
model_init, model_predict = model()
# Setup state
step = state.step or 0
params_initializer = lambda: model_init([-1] + list(inputs.input_shape))[1]
params = state.params or params_initializer()
opt_state = opt_init(params)
# jit model_predict and update so they're fast
jit_predict = jax.jit(model_predict) # for evaluation
@jax.jit
def update(i, opt_state, batch):
params = jax_opt.get_params(opt_state)
return opt_update(i,
jax.grad(loss)(params, batch, model_predict),
opt_state)
print()
train_stream = inputs.train_stream()
epoch_steps = itertools.chain(
[
1, # first epoch only 1 step
eval_frequency - 1
],
itertools.repeat(eval_frequency))
step_log(step, "Starting training")
for epoch, epoch_steps in epochs(train_steps, epoch_steps):
# Log separator
print()
# Timer
start_time = time.time()
for _ in range(epoch_steps):
# Train
opt_state = update(step, opt_state, next(train_stream))
step += 1
# LR log
if step == 1 or step % 10 == 0:
train_sw.scalar("training/learning rate",
lr_fun(step),
step=step)
# Timer
epoch_time = time.time() - start_time
step_log(
step,
"Ran %d train steps in %0.2f secs" % (epoch_steps, epoch_time))
if epoch_steps > 1:
train_sw.scalar("training/steps per second",
epoch_steps / epoch_time,
step=step)
# Evaluate
params = jax_opt.get_params(opt_state)
evaluate_train_and_eval(step=step,
inputs=inputs,
predict_fun=functools.partial(
jit_predict, params),
eval_steps=eval_steps,
train_sw=train_sw,
eval_sw=eval_sw,
history=history)
# Save state
save_state(State(params=params, step=step, history=history),
output_dir)
# Save Gin config
# Gin only tracks the used parameters, so we save it after the first epoch.
if epoch == 1:
save_gin(output_dir, train_sw)
# Flush summary writers
train_sw.writer.flush()
eval_sw.writer.flush()
step_log(step, "Training done")
return State(params=params, step=step, history=history)
def training_loop(
env,
eval_env,
env_name,
policy_and_value_net_fn,
policy_and_value_optimizer_fn,
output_dir,
epochs=EPOCHS,
n_optimizer_steps=N_OPTIMIZER_STEPS,
print_every_optimizer_steps=PRINT_EVERY_OPTIMIZER_STEP,
target_kl=0.01,
boundary=20,
max_timestep=None,
max_timestep_eval=20000,
random_seed=None,
gamma=GAMMA,
lambda_=LAMBDA,
epsilon=EPSILON,
c1=1.0,
c2=0.01,
eval_every_n=1000,
done_frac_for_policy_save=0.5,
enable_early_stopping=True,
n_evals=1,
len_history_for_policy=4,
eval_temperatures=(1.0, 0.5),
):
"""Runs the training loop for PPO, with fixed policy and value nets.
Args:
env: gym.Env to use for training.
eval_env: gym.Env to use for evaluation.
env_name: Name of the environment.
policy_and_value_net_fn: Function defining the policy and value network.
policy_and_value_optimizer_fn: Function defining the optimizer.
output_dir: Output dir.
epochs: Number of epochs to run for.
n_optimizer_steps: Number of optimizer steps.
print_every_optimizer_steps: How often to log during the policy optimization
process.
target_kl: Policy iteration early stopping.
boundary: We pad trajectories at integer multiples of this number.
max_timestep: If set to an integer, maximum number of time-steps in
a trajectory. Used in the collect procedure.
max_timestep_eval: If set to an integer, maximum number of time-steps in an
evaluation trajectory. Used in the collect procedure.
random_seed: Random seed.
gamma: Reward discount factor.
lambda_: N-step TD-error discount factor in GAE.
epsilon: Random action probability in epsilon-greedy sampling.
c1: Value loss coefficient.
c2: Entropy loss coefficient.
eval_every_n: How frequently to eval the policy.
done_frac_for_policy_save: Fraction of the trajectories that should be done
to checkpoint the policy.
enable_early_stopping: Whether to enable early stopping.
n_evals: Number of times to evaluate.
len_history_for_policy: How much of history to give to the policy.
eval_temperatures: Sequence of temperatures to try for categorical sampling
during evaluation.
"""
gfile.makedirs(output_dir)
# Create summary writers and history.
train_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "train"))
timing_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "timing"))
eval_sw = jaxboard.SummaryWriter(os.path.join(output_dir, "eval"))
train_sw.text("env_name", env_name)
timing_sw.text("env_name", env_name)
eval_sw.text("env_name", env_name)
jax_rng_key = trax.get_random_number_generator_and_set_seed(random_seed)
# Batch Observations Shape = [1, 1] + OBS, because we will eventually call
# policy and value networks on shape [B, T] +_OBS
batch_observations_shape = (1, 1) + env.observation_space.shape
observations_dtype = env.observation_space.dtype
assert isinstance(env.action_space, gym.spaces.Discrete)
n_actions = env.action_space.n
jax_rng_key, key1 = jax_random.split(jax_rng_key, num=2)
# Initialize the policy and value network.
policy_and_value_net_params, policy_and_value_net_apply = (
policy_and_value_net_fn(key1, batch_observations_shape,
observations_dtype, n_actions))
# Maybe restore the policy params. If there is nothing to restore, then
# iteration = 0 and policy_and_value_net_params are returned as is.
restore, policy_and_value_net_params, iteration = (maybe_restore_params(
output_dir, policy_and_value_net_params))
if restore:
logging.info("Restored parameters from iteration [%d]", iteration)
# We should start from the next iteration.
iteration += 1
policy_and_value_net_apply = jit(policy_and_value_net_apply)
# Initialize the optimizers.
policy_and_value_optimizer = (
policy_and_value_optimizer_fn(policy_and_value_net_params))
(policy_and_value_opt_state, policy_and_value_opt_update,
policy_and_value_get_params) = policy_and_value_optimizer
n_trajectories_done = 0
last_saved_at = 0
logging.info("Starting the PPO training loop.")
for i in range(iteration, epochs):
epoch_start_time = time.time()
# Params we'll use to collect the trajectories.
policy_and_value_net_params = policy_and_value_get_params(
policy_and_value_opt_state)
# A function to get the policy and value predictions.
def get_predictions(observations, rng=None):
"""Returns log-probs, value predictions and key back."""
key, key1 = jax_random.split(rng, num=2)
log_probs, value_preds = policy_and_value_net_apply(
observations, policy_and_value_net_params, rng=key1)
return log_probs, value_preds, key
# Evaluate the policy.
policy_eval_start_time = time.time()
if ((i + 1) % eval_every_n == 0) or (i == epochs - 1):
jax_rng_key, key = jax_random.split(jax_rng_key, num=2)
logging.vlog(1, "Epoch [% 6d] evaluating policy.", i)
reward_stats = evaluate_policy(
eval_env,
get_predictions,
temperatures=eval_temperatures,
max_timestep=max_timestep_eval,
n_evals=n_evals,
len_history_for_policy=len_history_for_policy,
rng=key)
write_eval_reward_summaries(reward_stats, eval_sw, epoch=i)
policy_eval_time = get_time(policy_eval_start_time)
trajectory_collection_start_time = time.time()
logging.vlog(1, "Epoch [% 6d] collecting trajectories.", i)
jax_rng_key, key = jax_random.split(jax_rng_key)
trajs, n_done, timing_info = collect_trajectories(
env,
policy_fn=get_predictions,
n_trajectories=env.batch_size,
max_timestep=max_timestep,
rng=key,
len_history_for_policy=len_history_for_policy,
reset=(i == 0) or restore,
epsilon=(10.0 / (i + 10.0))) # this is a different epsilon.
trajectory_collection_time = get_time(trajectory_collection_start_time)
logging.vlog(1, "Collecting trajectories took %0.2f msec.",
trajectory_collection_time)
avg_reward = float(sum(np.sum(traj[2]) for traj in trajs)) / len(trajs)
max_reward = max(np.sum(traj[2]) for traj in trajs)
min_reward = min(np.sum(traj[2]) for traj in trajs)
train_sw.scalar("train/reward_mean_truncated", avg_reward, step=i)
logging.vlog(1,
"Rewards avg=[%0.2f], max=[%0.2f], min=[%0.2f], all=%s",
avg_reward, max_reward, min_reward,
[float(np.sum(traj[2])) for traj in trajs])
logging.vlog(
1, "Trajectory Length average=[%0.2f], max=[%0.2f], min=[%0.2f]",
float(sum(len(traj[0]) for traj in trajs)) / len(trajs),
max(len(traj[0]) for traj in trajs),
min(len(traj[0]) for traj in trajs))
logging.vlog(2, "Trajectory Lengths: %s",
[len(traj[0]) for traj in trajs])
padding_start_time = time.time()
(_, reward_mask, padded_observations, padded_actions, padded_rewards,
padded_infos) = pad_trajectories(trajs, boundary=boundary)
padding_time = get_time(padding_start_time)
logging.vlog(1, "Padding trajectories took %0.2f msec.",
get_time(padding_start_time))
logging.vlog(1, "Padded Observations' shape [%s]",
str(padded_observations.shape))
logging.vlog(1, "Padded Actions' shape [%s]",
str(padded_actions.shape))
logging.vlog(1, "Padded Rewards' shape [%s]",
str(padded_rewards.shape))
# Some assertions.
B, T = padded_actions.shape # pylint: disable=invalid-name
assert (B, T) == padded_rewards.shape
assert (B, T) == reward_mask.shape
assert (B, T + 1) == padded_observations.shape[:2]
assert (B, T +
1) + env.observation_space.shape == padded_observations.shape
log_prob_recompute_start_time = time.time()
assert ("log_prob_actions" in padded_infos
and "value_predictions" in padded_infos)
# These are the actual log-probabs and value predictions seen while picking
# the actions.
actual_log_probabs_traj = padded_infos["log_prob_actions"]
actual_value_predictions_traj = padded_infos["value_predictions"]
assert (B, T) == actual_log_probabs_traj.shape[:2]
A = actual_log_probabs_traj.shape[2] # pylint: disable=invalid-name
assert (B, T, 1) == actual_value_predictions_traj.shape
# TODO(afrozm): log-probabs doesn't need to be (B, T+1, A) it can do with
# (B, T, A), so make that change throughout.
# NOTE: We don't have the log-probabs and value-predictions for the last
# observation, so we re-calculate for everything, but use the original ones
# for all but the last time-step.
jax_rng_key, key = jax_random.split(jax_rng_key)
log_probabs_traj, value_predictions_traj, _ = get_predictions(
padded_observations, rng=key)
assert (B, T + 1, A) == log_probabs_traj.shape
assert (B, T + 1, 1) == value_predictions_traj.shape
# Concatenate the last time-step's log-probabs and value predictions to the
# actual log-probabs and value predictions and use those going forward.
log_probabs_traj = np.concatenate(
(actual_log_probabs_traj, log_probabs_traj[:, -1:, :]), axis=1)
value_predictions_traj = np.concatenate(
(actual_value_predictions_traj, value_predictions_traj[:, -1:, :]),
axis=1)
log_prob_recompute_time = get_time(log_prob_recompute_start_time)
# Linear annealing from 0.1 to 0.0
# epsilon_schedule = epsilon if epochs == 1 else epsilon * (1.0 -
# (i /
# (epochs - 1)))
# Constant epsilon.
epsilon_schedule = epsilon
# Compute value and ppo losses.
jax_rng_key, key1 = jax_random.split(jax_rng_key, num=2)
logging.vlog(2, "Starting to compute P&V loss.")
loss_compute_start_time = time.time()
cur_combined_loss, cur_ppo_loss, cur_value_loss, entropy_bonus = (
combined_loss(policy_and_value_net_params,
log_probabs_traj,
value_predictions_traj,
policy_and_value_net_apply,
padded_observations,
padded_actions,
padded_rewards,
reward_mask,
gamma=gamma,
lambda_=lambda_,
epsilon=epsilon_schedule,
c1=c1,
c2=c2,
rng=key1))
loss_compute_time = get_time(loss_compute_start_time)
logging.vlog(
1,
"Calculating P&V loss [%10.2f(%10.2f, %10.2f, %10.2f)] took %0.2f msec.",
cur_combined_loss, cur_value_loss, cur_ppo_loss, entropy_bonus,
get_time(loss_compute_start_time))
jax_rng_key, key1 = jax_random.split(jax_rng_key, num=2)
logging.vlog(1, "Policy and Value Optimization")
optimization_start_time = time.time()
keys = jax_random.split(key1, num=n_optimizer_steps)
for j in range(n_optimizer_steps):
k1, k2, k3 = jax_random.split(keys[j], num=3)
t = time.time()
# Update the optimizer state.
policy_and_value_opt_state = policy_and_value_opt_step(
j,
policy_and_value_opt_state,
policy_and_value_opt_update,
policy_and_value_get_params,
policy_and_value_net_apply,
log_probabs_traj,
value_predictions_traj,
padded_observations,
padded_actions,
padded_rewards,
reward_mask,
c1=c1,
c2=c2,
gamma=gamma,
lambda_=lambda_,
epsilon=epsilon_schedule,
rng=k1)
# Compute the approx KL for early stopping.
new_policy_and_value_net_params = policy_and_value_get_params(
policy_and_value_opt_state)
log_probab_actions_new, _ = policy_and_value_net_apply(
padded_observations, new_policy_and_value_net_params, rng=k2)
approx_kl = approximate_kl(log_probab_actions_new,
log_probabs_traj, reward_mask)
early_stopping = enable_early_stopping and approx_kl > 1.5 * target_kl
if early_stopping:
logging.vlog(
1,
"Early stopping policy and value optimization at iter: %d, "
"with approx_kl: %0.2f", j, approx_kl)
# We don't return right-away, we want the below to execute on the last
# iteration.
t2 = time.time()
if (((j + 1) % print_every_optimizer_steps == 0)
or (j == n_optimizer_steps - 1) or early_stopping):
# Compute and log the loss.
(loss_combined, loss_ppo, loss_value,
entropy_bonus) = (combined_loss(
new_policy_and_value_net_params,
log_probabs_traj,
value_predictions_traj,
policy_and_value_net_apply,
padded_observations,
padded_actions,
padded_rewards,
reward_mask,
gamma=gamma,
lambda_=lambda_,
epsilon=epsilon_schedule,
c1=c1,
c2=c2,
rng=k3))
logging.vlog(
1, "One Policy and Value grad desc took: %0.2f msec",
get_time(t, t2))
logging.vlog(
1, "Combined Loss(value, ppo, entropy_bonus) [%10.2f] ->"
" [%10.2f(%10.2f,%10.2f,%10.2f)]", cur_combined_loss,
loss_combined, loss_value, loss_ppo, entropy_bonus)
if early_stopping:
break
optimization_time = get_time(optimization_start_time)
logging.vlog(
1, "Total Combined Loss reduction [%0.2f]%%",
(100 *
(cur_combined_loss - loss_combined) / np.abs(cur_combined_loss)))
# Save parameters every time we see the end of at least a fraction of batch
# number of trajectories that are done (not completed -- completed includes
# truncated and done).
# Also don't save too frequently, enforce a minimum gap.
# Or if this is the last iteration.
policy_save_start_time = time.time()
n_trajectories_done += n_done
# TODO(afrozm): Refactor to trax.save_state.
if ((
(n_trajectories_done >= done_frac_for_policy_save * env.batch_size)
and (i - last_saved_at > eval_every_n) and
(((i + 1) % eval_every_n == 0))) or (i == epochs - 1)):
logging.vlog(1, "Epoch [% 6d] saving model.", i)
old_model_files = gfile.glob(
os.path.join(output_dir, "model-??????.pkl"))
params_file = os.path.join(output_dir, "model-%06d.pkl" % i)
with gfile.GFile(params_file, "wb") as f:
pickle.dump(policy_and_value_net_params, f)
# Remove the old model files.
for path in old_model_files:
gfile.remove(path)
# Reset this number.
n_trajectories_done = 0
last_saved_at = i
policy_save_time = get_time(policy_save_start_time)
epoch_time = get_time(epoch_start_time)
logging.info(
"Epoch [% 6d], Reward[min, max, avg] [%5.2f,%5.2f,%5.2f], Combined"
" Loss(value, ppo, entropy) [%2.5f(%2.5f,%2.5f,%2.5f)]", i,
min_reward, max_reward, avg_reward, loss_combined, loss_value,
loss_ppo, entropy_bonus)
timing_dict = {
"epoch": epoch_time,
"policy_eval": policy_eval_time,
"trajectory_collection": trajectory_collection_time,
"padding": padding_time,
"log_prob_recompute": log_prob_recompute_time,
"loss_compute": loss_compute_time,
"optimization": optimization_time,
"policy_save": policy_save_time,
}
timing_dict.update(timing_info)
for k, v in timing_dict.items():
timing_sw.scalar("timing/%s" % k, v, step=i)
max_key_len = max(len(k) for k in timing_dict)
timing_info_list = [
"%s : % 10.2f" % (k.rjust(max_key_len + 1), v)
for k, v in sorted(timing_dict.items())
]
logging.info("Epoch [% 6d], Timings: \n%s", i,
"\n".join(timing_info_list))
# Reset restore.
restore = False
# Flush summary writers once in a while.
if (i + 1) % 1000 == 0 or i == epochs - 1:
train_sw.flush()
timing_sw.flush()
eval_sw.flush()
def __init__(
self,
train_env,
eval_env,
policy_and_value_model,
policy_and_value_optimizer_fn,
policy_and_value_two_towers,
output_dir,
n_optimizer_steps,
print_every_optimizer_steps,
target_kl,
boundary,
max_timestep,
max_timestep_eval,
random_seed,
gamma,
lambda_,
c1,
c2,
eval_every_n,
done_frac_for_policy_save,
n_evals,
len_history_for_policy,
eval_temperatures,
):
self._train_env = train_env
self._eval_env = eval_env
self._n_optimizer_steps = n_optimizer_steps
self._print_every_optimizer_steps = print_every_optimizer_steps
self._target_kl = target_kl
self._boundary = boundary
self._max_timestep = max_timestep
self._max_timestep_eval = max_timestep_eval
self._gamma = gamma
self._lambda_ = lambda_
self._c1 = c1
self._c2 = c2
self._eval_every_n = eval_every_n
self._done_frac_for_policy_save = done_frac_for_policy_save
self._n_evals = n_evals
self._len_history_for_policy = len_history_for_policy
self._eval_temperatures = eval_temperatures
assert isinstance(self._train_env.action_space, gym.spaces.Discrete)
n_actions = self._train_env.action_space.n
# Batch Observations Shape = [1, 1] + OBS, because we will eventually call
# policy and value networks on shape [B, T] +_OBS
batch_observations_shape = (1, 1) + self._train_env.observation_space.shape
observations_dtype = self._train_env.observation_space.dtype
self._rng = trax.get_random_number_generator_and_set_seed(random_seed)
self._rng, key1 = jax_random.split(self._rng, num=2)
# Initialize the policy and value network.
policy_and_value_net_params, policy_and_value_net_apply = (
policy_and_value_net(
rng_key=key1,
batch_observations_shape=batch_observations_shape,
observations_dtype=observations_dtype,
n_actions=n_actions,
bottom_layers_fn=policy_and_value_model,
two_towers=policy_and_value_two_towers,
)
)
self._policy_and_value_net_apply = jit(policy_and_value_net_apply)
# Maybe restore the policy params. If there is nothing to restore, then
# iteration = 0 and policy_and_value_net_params are returned as is.
restored, policy_and_value_net_params, self._epoch = (
maybe_restore_params(output_dir, policy_and_value_net_params))
if restored:
logging.info("Restored parameters from iteration [%d]", self._epoch)
# We should start from the next iteration.
self._epoch += 1
# Initialize the optimizers.
policy_and_value_optimizer = (
policy_and_value_optimizer_fn(policy_and_value_net_params))
(self._policy_and_value_opt_state, self._policy_and_value_opt_update,
self._policy_and_value_get_params) = policy_and_value_optimizer
self._output_dir = output_dir
gfile.makedirs(self._output_dir)
# Create summary writers and history.
self._train_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "train"))
self._timing_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "timing"))
self._eval_sw = jaxboard.SummaryWriter(
os.path.join(self._output_dir, "eval"))
self._should_reset = True
self._n_trajectories_done = 0
self._last_saved_at = 0
def __init__(
self,
train_env,
eval_env,
output_dir,
policy_trainer_class,
n_real_epochs=10,
data_eval_frac=0.125,
model_train_batch_size=64,
n_model_initial_train_steps=1000,
n_model_train_steps_per_epoch=1000,
simulated_env_problem_class=(
simulated_env_problem.SerializedSequenceSimulatedEnvProblem),
simulated_batch_size=16,
n_simulated_epochs=1000,
trajectory_dump_dir=None,
initial_trajectory_dir=None,
initial_trajectory_mix_prob=0.5,
initial_model=None,
init_policy_from_world_model=False,
**kwargs):
super(SimPLe, self).__init__(train_env, eval_env, output_dir, **kwargs)
self._policy_dir = os.path.join(output_dir, "policy")
self._model_dir = os.path.join(output_dir, "model")
# Initialize the policy trainer lazily, so in case of initializing the
# policy from world model checkpoint, the trainer will try to load the
# checkpoint _after_ it's been created in train_model().
self._policy_trainer_fn = functools.partial(
policy_trainer_class,
train_env=train_env,
eval_env=eval_env,
output_dir=self._policy_dir,
async_mode=self._async_mode,
init_policy_from_world_model_output_dir=(
self._model_dir if init_policy_from_world_model else None),
)
self._policy_trainer = None
self._n_real_epochs = n_real_epochs
self._model_train_batch_size = model_train_batch_size
self._n_model_initial_train_steps = n_model_initial_train_steps
self._n_model_train_steps_per_epoch = n_model_train_steps_per_epoch
self._data_eval_frac = data_eval_frac
gfile.makedirs(self._model_dir)
if initial_model is not None:
gfile.copy(
initial_model,
os.path.join(self._model_dir, "model.pkl"),
overwrite=True,
)
self._initial_model = initial_model
self._initial_trajectories = None
self._sim_env = simulated_env_problem_class(
batch_size=None,
observation_space=train_env.observation_space,
action_space=train_env.action_space,
reward_range=train_env.reward_range,
discrete_rewards=train_env.discrete_rewards,
history_stream=None, # TODO(pkozakowski): Support this.
output_dir=self._model_dir,
)
self._simulated_batch_size = simulated_batch_size
self._n_simulated_epochs = n_simulated_epochs
# If trajectory_dump_dir is not provided explicitly, save the trajectories
# in output_dir.
if trajectory_dump_dir is None:
trajectory_dump_dir = os.path.join(output_dir, "trajectories")
self._trajectory_dump_root_dir = trajectory_dump_dir
self._initial_trajectory_dir = initial_trajectory_dir
self._initial_trajectory_mix_prob = initial_trajectory_mix_prob
self._summary_writer = jaxboard.SummaryWriter(self._output_dir)
self._simple_epoch = 0
self._policy_epoch = 0
self._model_train_step = 0