def test_reward_overwrite():
"""Test that reward wrapper actually overwrites base rewards."""
env_name = "Pendulum-v0"
num_envs = 3
env = util.make_vec_env(env_name, num_envs)
reward_fn = FunkyReward()
wrapped_env = reward_wrapper.RewardVecEnvWrapper(env, reward_fn)
policy = RandomPolicy(env.observation_space, env.action_space)
sample_until = rollout.min_episodes(10)
default_stats = rollout.rollout_stats(
rollout.generate_trajectories(policy, env, sample_until))
wrapped_stats = rollout.rollout_stats(
rollout.generate_trajectories(policy, wrapped_env, sample_until))
# Pendulum-v0 always has negative rewards
assert default_stats["return_max"] < 0
# ours gives between 1 * traj_len and num_envs * traj_len reward
# (trajectories are all constant length of 200 in Pendulum)
steps = wrapped_stats["len_mean"]
assert wrapped_stats["return_min"] == 1 * steps
assert wrapped_stats["return_max"] == num_envs * steps
# check that wrapped reward is negative (all pendulum rewards is negative)
# and other rewards are non-negative
rand_act, _, _, _ = policy.step(wrapped_env.reset())
_, rew, _, infos = wrapped_env.step(rand_act)
assert np.all(rew >= 0)
assert np.all([info_dict["wrapped_env_rew"] < 0 for info_dict in infos])
def eval_policy(
rl_algo: Union[base_class.BaseAlgorithm, policies.BasePolicy],
venv: vec_env.VecEnv,
n_episodes_eval: int,
) -> Mapping[str, float]:
"""Evaluation of imitation learned policy.
Args:
rl_algo: Algorithm to evaluate.
venv: Environment to evaluate on.
n_episodes_eval: The number of episodes to average over when calculating
the average episode reward of the imitation policy for return.
Returns:
A dictionary with two keys. "imit_stats" gives the return value of
`rollout_stats()` on rollouts test-reward-wrapped environment, using the final
policy (remember that the ground-truth reward can be recovered from the
"monitor_return" key). "expert_stats" gives the return value of
`rollout_stats()` on the expert demonstrations loaded from `rollout_path`.
"""
sample_until_eval = rollout.make_min_episodes(n_episodes_eval)
trajs = rollout.generate_trajectories(
rl_algo,
venv,
sample_until=sample_until_eval,
)
return rollout.rollout_stats(trajs)
def test_policy(self, *, min_episodes: int = 10) -> dict:
"""Test current imitation policy on environment & give some rollout stats.
Args:
min_episodes: Minimum number of rolled-out episodes.
Returns:
rollout statistics collected by `imitation.utils.rollout.rollout_stats()`.
"""
trajs = rollout.generate_trajectories(
self.policy,
self.env,
sample_until=rollout.min_episodes(min_episodes))
reward_stats = rollout.rollout_stats(trajs)
return reward_stats
def test_rollout_stats():
"""Applying `ObsRewIncrementWrapper` halves the reward mean.
`rollout_stats` should reflect this.
"""
env = gym.make("CartPole-v1")
env = bench.Monitor(env, None)
env = ObsRewHalveWrapper(env)
venv = vec_env.DummyVecEnv([lambda: env])
with serialize.load_policy("zero", "UNUSED", venv) as policy:
trajs = rollout.generate_trajectories(policy, venv, rollout.min_episodes(10))
s = rollout.rollout_stats(trajs)
np.testing.assert_allclose(s["return_mean"], s["monitor_return_mean"] / 2)
np.testing.assert_allclose(s["return_std"], s["monitor_return_std"] / 2)
np.testing.assert_allclose(s["return_min"], s["monitor_return_min"] / 2)
np.testing.assert_allclose(s["return_max"], s["monitor_return_max"] / 2)
def test_policy(self, *, n_trajectories=10, true_reward=True):
"""Test current imitation policy on environment & give some rollout stats.
Args:
n_trajectories (int): number of rolled-out trajectories.
true_reward (bool): should this use ground truth reward from underlying
environment (True), or imitation reward (False)?
Returns:
dict: rollout statistics collected by
`imitation.utils.rollout.rollout_stats()`.
"""
self.imitation_trainer.set_env(self.venv)
trajs = rollout.generate_trajectories(
self.imitation_trainer,
self.venv if true_reward else self.wrapped_env,
sample_until=rollout.min_episodes(n_trajectories),
)
reward_stats = rollout.rollout_stats(trajs)
return reward_stats
def rollouts_and_policy(
_run,
_seed: int,
env_name: str,
total_timesteps: int,
*,
log_dir: str,
num_vec: int,
parallel: bool,
max_episode_steps: Optional[int],
normalize: bool,
normalize_kwargs: dict,
init_rl_kwargs: dict,
n_episodes_eval: int,
reward_type: Optional[str],
reward_path: Optional[str],
rollout_save_interval: int,
rollout_save_final: bool,
rollout_save_n_timesteps: Optional[int],
rollout_save_n_episodes: Optional[int],
policy_save_interval: int,
policy_save_final: bool,
init_tensorboard: bool,
) -> dict:
"""Trains an expert policy from scratch and saves the rollouts and policy.
Checkpoints:
At applicable training steps `step` (where step is either an integer or
"final"):
- Policies are saved to `{log_dir}/policies/{step}/`.
- Rollouts are saved to `{log_dir}/rollouts/{step}.pkl`.
Args:
env_name: The gym.Env name. Loaded as VecEnv.
total_timesteps: Number of training timesteps in `model.learn()`.
log_dir: The root directory to save metrics and checkpoints to.
num_vec: Number of environments in VecEnv.
parallel: If True, then use DummyVecEnv. Otherwise use SubprocVecEnv.
max_episode_steps: If not None, then environments are wrapped by
TimeLimit so that they have at most `max_episode_steps` steps per
episode.
normalize: If True, then rescale observations and reward.
normalize_kwargs: kwargs for `VecNormalize`.
init_rl_kwargs: kwargs for `init_rl`.
n_episodes_eval: The number of episodes to average over when calculating
the average ground truth reward return of the final policy.
reward_type: If provided, then load the serialized reward of this type,
wrapping the environment in this reward. This is useful to test
whether a reward model transfers. For more information, see
`imitation.rewards.serialize.load_reward`.
reward_path: A specifier, such as a path to a file on disk, used by
reward_type to load the reward model. For more information, see
`imitation.rewards.serialize.load_reward`.
rollout_save_interval: The number of training updates in between
intermediate rollout saves. If the argument is nonpositive, then
don't save intermediate updates.
rollout_save_final: If True, then save rollouts right after training is
finished.
rollout_save_n_timesteps: The minimum number of timesteps saved in every
file. Could be more than `rollout_save_n_timesteps` because
trajectories are saved by episode rather than by transition.
Must set exactly one of `rollout_save_n_timesteps`
and `rollout_save_n_episodes`.
rollout_save_n_episodes: The number of episodes saved in every
file. Must set exactly one of `rollout_save_n_timesteps` and
`rollout_save_n_episodes`.
policy_save_interval: The number of training updates between saves. Has
the same semantics are `rollout_save_interval`.
policy_save_final: If True, then save the policy right after training is
finished.
init_tensorboard: If True, then write tensorboard logs to {log_dir}/sb_tb
and "output/summary/...".
Returns:
The return value of `rollout_stats()` using the final policy.
"""
os.makedirs(log_dir, exist_ok=True)
sacred_util.build_sacred_symlink(log_dir, _run)
sample_until = rollout.make_sample_until(rollout_save_n_timesteps,
rollout_save_n_episodes)
eval_sample_until = rollout.min_episodes(n_episodes_eval)
with networks.make_session():
tf.logging.set_verbosity(tf.logging.INFO)
logger.configure(folder=osp.join(log_dir, "rl"),
format_strs=["tensorboard", "stdout"])
rollout_dir = osp.join(log_dir, "rollouts")
policy_dir = osp.join(log_dir, "policies")
os.makedirs(rollout_dir, exist_ok=True)
os.makedirs(policy_dir, exist_ok=True)
if init_tensorboard:
sb_tensorboard_dir = osp.join(log_dir, "sb_tb")
# Convert sacred's ReadOnlyDict to dict so we can modify on next line.
init_rl_kwargs = dict(init_rl_kwargs)
init_rl_kwargs["tensorboard_log"] = sb_tensorboard_dir
venv = util.make_vec_env(
env_name,
num_vec,
seed=_seed,
parallel=parallel,
log_dir=log_dir,
max_episode_steps=max_episode_steps,
)
log_callbacks = []
with contextlib.ExitStack() as stack:
if reward_type is not None:
reward_fn_ctx = load_reward(reward_type, reward_path, venv)
reward_fn = stack.enter_context(reward_fn_ctx)
venv = RewardVecEnvWrapper(venv, reward_fn)
log_callbacks.append(venv.log_callback)
tf.logging.info(
f"Wrapped env in reward {reward_type} from {reward_path}.")
vec_normalize = None
if normalize:
venv = vec_normalize = VecNormalize(venv, **normalize_kwargs)
policy = util.init_rl(venv, verbose=1, **init_rl_kwargs)
# Make callback to save intermediate artifacts during training.
step = 0
def callback(locals_: dict, _) -> bool:
nonlocal step
step += 1
policy = locals_["self"]
# TODO(adam): make logging frequency configurable
for callback in log_callbacks:
callback(sb_logger)
if rollout_save_interval > 0 and step % rollout_save_interval == 0:
save_path = osp.join(rollout_dir, f"{step}.pkl")
rollout.rollout_and_save(save_path, policy, venv,
sample_until)
if policy_save_interval > 0 and step % policy_save_interval == 0:
output_dir = os.path.join(policy_dir, f"{step:05d}")
serialize.save_stable_model(output_dir, policy,
vec_normalize)
policy.learn(total_timesteps, callback=callback)
# Save final artifacts after training is complete.
if rollout_save_final:
save_path = osp.join(rollout_dir, "final.pkl")
rollout.rollout_and_save(save_path, policy, venv, sample_until)
if policy_save_final:
output_dir = os.path.join(policy_dir, "final")
serialize.save_stable_model(output_dir, policy, vec_normalize)
# Final evaluation of expert policy.
trajs = rollout.generate_trajectories(policy, venv,
eval_sample_until)
stats = rollout.rollout_stats(trajs)
return stats
def eval_policy(
_run,
_seed: int,
env_name: str,
eval_n_timesteps: Optional[int],
eval_n_episodes: Optional[int],
num_vec: int,
parallel: bool,
render: bool,
render_fps: int,
log_dir: str,
policy_type: str,
policy_path: str,
reward_type: Optional[str] = None,
reward_path: Optional[str] = None,
max_episode_steps: Optional[int] = None,
):
"""Rolls a policy out in an environment, collecting statistics.
Args:
_seed: generated by Sacred.
env_name: Gym environment identifier.
eval_n_timesteps: Minimum number of timesteps to evaluate for. Set exactly
one of `eval_n_episodes` and `eval_n_timesteps`.
eval_n_episodes: Minimum number of episodes to evaluate for. Set exactly
one of `eval_n_episodes` and `eval_n_timesteps`.
num_vec: Number of environments to run simultaneously.
parallel: If True, use `SubprocVecEnv` for true parallelism; otherwise,
uses `DummyVecEnv`.
max_episode_steps: If not None, then environments are wrapped by
TimeLimit so that they have at most `max_episode_steps` steps per
episode.
render: If True, renders interactively to the screen.
log_dir: The directory to log intermediate output to. (As of 2019-07-19
this is just episode-by-episode reward from bench.Monitor.)
policy_type: A unique identifier for the saved policy,
defined in POLICY_CLASSES.
policy_path: A path to the serialized policy.
reward_type: If specified, overrides the environment reward with
a reward of this.
reward_path: If reward_type is specified, the path to a serialized reward
of `reward_type` to override the environment reward with.
Returns:
Return value of `imitation.util.rollout.rollout_stats()`.
"""
os.makedirs(log_dir, exist_ok=True)
sacred_util.build_sacred_symlink(log_dir, _run)
tf.logging.set_verbosity(tf.logging.INFO)
tf.logging.info("Logging to %s", log_dir)
sample_until = rollout.make_sample_until(eval_n_timesteps, eval_n_episodes)
venv = util.make_vec_env(
env_name,
num_vec,
seed=_seed,
parallel=parallel,
log_dir=log_dir,
max_episode_steps=max_episode_steps,
)
if render:
venv = InteractiveRender(venv, render_fps)
# TODO(adam): add support for videos using VideoRecorder?
with contextlib.ExitStack() as stack:
if reward_type is not None:
reward_fn_ctx = load_reward(reward_type, reward_path, venv)
reward_fn = stack.enter_context(reward_fn_ctx)
venv = reward_wrapper.RewardVecEnvWrapper(venv, reward_fn)
tf.logging.info(
f"Wrapped env in reward {reward_type} from {reward_path}.")
with serialize.load_policy(policy_type, policy_path, venv) as policy:
trajs = rollout.generate_trajectories(policy, venv, sample_until)
return rollout.rollout_stats(trajs)
def train(
_run,
_seed: int,
algorithm: str,
env_name: str,
num_vec: int,
parallel: bool,
max_episode_steps: Optional[int],
rollout_path: str,
n_expert_demos: Optional[int],
log_dir: str,
total_timesteps: int,
n_episodes_eval: int,
init_tensorboard: bool,
checkpoint_interval: int,
gen_batch_size: int,
init_rl_kwargs: Mapping,
algorithm_kwargs: Mapping[str, Mapping],
discrim_net_kwargs: Mapping[str, Mapping],
) -> dict:
"""Train an adversarial-network-based imitation learning algorithm.
Checkpoints:
- DiscrimNets are saved to `f"{log_dir}/checkpoints/{step}/discrim/"`,
where step is either the training round or "final".
- Generator policies are saved to `f"{log_dir}/checkpoints/{step}/gen_policy/"`.
Args:
_seed: Random seed.
algorithm: A case-insensitive string determining which adversarial imitation
learning algorithm is executed. Either "airl" or "gail".
env_name: The environment to train in.
num_vec: Number of `gym.Env` to vectorize.
parallel: Whether to use "true" parallelism. If True, then use `SubProcVecEnv`.
Otherwise, use `DummyVecEnv` which steps through environments serially.
max_episode_steps: If not None, then a TimeLimit wrapper is applied to each
environment to artificially limit the maximum number of timesteps in an
episode.
rollout_path: Path to pickle containing list of Trajectories. Used as
expert demonstrations.
n_expert_demos: The number of expert trajectories to actually use
after loading them from `rollout_path`.
If None, then use all available trajectories.
If `n_expert_demos` is an `int`, then use exactly `n_expert_demos`
trajectories, erroring if there aren't enough trajectories. If there are
surplus trajectories, then use the first `n_expert_demos` trajectories and
drop the rest.
log_dir: Directory to save models and other logging to.
total_timesteps: The number of transitions to sample from the environment
during training.
n_episodes_eval: The number of episodes to average over when calculating
the average episode reward of the imitation policy for return.
init_tensorboard: If True, then write tensorboard logs to `{log_dir}/sb_tb`.
checkpoint_interval: Save the discriminator and generator models every
`checkpoint_interval` rounds and after training is complete. If 0,
then only save weights after training is complete. If <0, then don't
save weights at all.
gen_batch_size: Batch size for generator updates. Sacred automatically uses
this to calculate `n_steps` in `init_rl_kwargs`. In the script body, this
is only used in sanity checks.
init_rl_kwargs: Keyword arguments for `init_rl`, the RL algorithm initialization
utility function.
algorithm_kwargs: Keyword arguments for the `GAIL` or `AIRL` constructor
that can apply to either constructor. Unlike a regular kwargs argument, this
argument can only have the following keys: "shared", "airl", and "gail".
`algorithm_kwargs["airl"]`, if it is provided, is a kwargs `Mapping` passed
to the `AIRL` constructor when `algorithm == "airl"`. Likewise
`algorithm_kwargs["gail"]` is passed to the `GAIL` constructor when
`algorithm == "gail"`. `algorithm_kwargs["shared"]`, if provided, is passed
to both the `AIRL` and `GAIL` constructors. Duplicate keyword argument keys
between `algorithm_kwargs["shared"]` and `algorithm_kwargs["airl"]` (or
"gail") leads to an error.
discrim_net_kwargs: Keyword arguments for the `DiscrimNet` constructor. Unlike a
regular kwargs argument, this argument can only have the following keys:
"shared", "airl", "gail". These keys have the same meaning as they do in
`algorithm_kwargs`.
Returns:
A dictionary with two keys. "imit_stats" gives the return value of
`rollout_stats()` on rollouts test-reward-wrapped environment, using the final
policy (remember that the ground-truth reward can be recovered from the
"monitor_return" key). "expert_stats" gives the return value of
`rollout_stats()` on the expert demonstrations loaded from `rollout_path`.
"""
if gen_batch_size % num_vec != 0:
raise ValueError(
f"num_vec={num_vec} must evenly divide gen_batch_size={gen_batch_size}."
)
allowed_keys = {"shared", "gail", "airl"}
if not discrim_net_kwargs.keys() <= allowed_keys:
raise ValueError(
f"Invalid discrim_net_kwargs.keys()={discrim_net_kwargs.keys()}. "
f"Allowed keys: {allowed_keys}"
)
if not algorithm_kwargs.keys() <= allowed_keys:
raise ValueError(
f"Invalid discrim_net_kwargs.keys()={algorithm_kwargs.keys()}. "
f"Allowed keys: {allowed_keys}"
)
if not os.path.exists(rollout_path):
raise ValueError(f"File at rollout_path={rollout_path} does not exist.")
expert_trajs = types.load(rollout_path)
if n_expert_demos is not None:
if not len(expert_trajs) >= n_expert_demos:
raise ValueError(
f"Want to use n_expert_demos={n_expert_demos} trajectories, but only "
f"{len(expert_trajs)} are available via {rollout_path}."
)
expert_trajs = expert_trajs[:n_expert_demos]
expert_transitions = rollout.flatten_trajectories(expert_trajs)
total_timesteps = int(total_timesteps)
logging.info("Logging to %s", log_dir)
logger.configure(log_dir, ["tensorboard", "stdout"])
os.makedirs(log_dir, exist_ok=True)
sacred_util.build_sacred_symlink(log_dir, _run)
venv = util.make_vec_env(
env_name,
num_vec,
seed=_seed,
parallel=parallel,
log_dir=log_dir,
max_episode_steps=max_episode_steps,
)
# if init_tensorboard:
# tensorboard_log = osp.join(log_dir, "sb_tb")
# else:
# tensorboard_log = None
gen_algo = util.init_rl(
# FIXME(sam): ignoring tensorboard_log is a hack to prevent SB3 from
# re-configuring the logger (SB3 issue #109). See init_rl() for details.
# TODO(shwang): Let's get rid of init_rl after SB3 issue #109 is fixed?
# Besides sidestepping #109, init_rl is just a stub function.
venv,
**init_rl_kwargs,
)
discrim_kwargs_shared = discrim_net_kwargs.get("shared", {})
discrim_kwargs_algo = discrim_net_kwargs.get(algorithm, {})
final_discrim_kwargs = dict(**discrim_kwargs_shared, **discrim_kwargs_algo)
algorithm_kwargs_shared = algorithm_kwargs.get("shared", {})
algorithm_kwargs_algo = algorithm_kwargs.get(algorithm, {})
final_algorithm_kwargs = dict(
**algorithm_kwargs_shared,
**algorithm_kwargs_algo,
)
if algorithm.lower() == "gail":
algo_cls = adversarial.GAIL
elif algorithm.lower() == "airl":
algo_cls = adversarial.AIRL
else:
raise ValueError(f"Invalid value algorithm={algorithm}.")
trainer = algo_cls(
venv=venv,
expert_data=expert_transitions,
gen_algo=gen_algo,
log_dir=log_dir,
discrim_kwargs=final_discrim_kwargs,
**final_algorithm_kwargs,
)
def callback(round_num):
if checkpoint_interval > 0 and round_num % checkpoint_interval == 0:
save(trainer, os.path.join(log_dir, "checkpoints", f"{round_num:05d}"))
trainer.train(total_timesteps, callback)
# Save final artifacts.
if checkpoint_interval >= 0:
save(trainer, os.path.join(log_dir, "checkpoints", "final"))
# Final evaluation of imitation policy.
results = {}
sample_until_eval = rollout.min_episodes(n_episodes_eval)
trajs = rollout.generate_trajectories(
trainer.gen_algo, trainer.venv_train_norm, sample_until=sample_until_eval
)
results["expert_stats"] = rollout.rollout_stats(expert_trajs)
results["imit_stats"] = rollout.rollout_stats(trajs)
return results
def eval_policy(
_run,
_seed: int,
env_name: str,
eval_n_timesteps: Optional[int],
eval_n_episodes: Optional[int],
num_vec: int,
parallel: bool,
render: bool,
render_fps: int,
videos: bool,
video_kwargs: Mapping[str, Any],
log_dir: str,
policy_type: str,
policy_path: str,
reward_type: Optional[str] = None,
reward_path: Optional[str] = None,
max_episode_steps: Optional[int] = None,
):
"""Rolls a policy out in an environment, collecting statistics.
Args:
_seed: generated by Sacred.
env_name: Gym environment identifier.
eval_n_timesteps: Minimum number of timesteps to evaluate for. Set exactly
one of `eval_n_episodes` and `eval_n_timesteps`.
eval_n_episodes: Minimum number of episodes to evaluate for. Set exactly
one of `eval_n_episodes` and `eval_n_timesteps`.
num_vec: Number of environments to run simultaneously.
parallel: If True, use `SubprocVecEnv` for true parallelism; otherwise,
uses `DummyVecEnv`.
max_episode_steps: If not None, then environments are wrapped by
TimeLimit so that they have at most `max_episode_steps` steps per
episode.
render: If True, renders interactively to the screen.
render_fps: The target number of frames per second to render on screen.
videos: If True, saves videos to `log_dir`.
video_kwargs: Keyword arguments passed through to `video_wrapper.VideoWrapper`.
log_dir: The directory to log intermediate output to, such as episode reward.
policy_type: A unique identifier for the saved policy,
defined in POLICY_CLASSES.
policy_path: A path to the serialized policy.
reward_type: If specified, overrides the environment reward with
a reward of this.
reward_path: If reward_type is specified, the path to a serialized reward
of `reward_type` to override the environment reward with.
Returns:
Return value of `imitation.util.rollout.rollout_stats()`.
"""
os.makedirs(log_dir, exist_ok=True)
sacred_util.build_sacred_symlink(log_dir, _run)
logging.basicConfig(level=logging.INFO)
logging.info("Logging to %s", log_dir)
sample_until = rollout.make_sample_until(eval_n_timesteps, eval_n_episodes)
post_wrappers = [video_wrapper_factory(log_dir, **video_kwargs)
] if videos else None
venv = util.make_vec_env(
env_name,
num_vec,
seed=_seed,
parallel=parallel,
log_dir=log_dir,
max_episode_steps=max_episode_steps,
post_wrappers=post_wrappers,
)
try:
if render:
# As of July 31, 2020, DummyVecEnv rendering only works with num_vec=1
# due to a bug on Stable Baselines 3.
venv = InteractiveRender(venv, render_fps)
if reward_type is not None:
reward_fn = load_reward(reward_type, reward_path, venv)
venv = reward_wrapper.RewardVecEnvWrapper(venv, reward_fn)
logging.info(
f"Wrapped env in reward {reward_type} from {reward_path}.")
policy = serialize.load_policy(policy_type, policy_path, venv)
trajs = rollout.generate_trajectories(policy, venv, sample_until)
return rollout.rollout_stats(trajs)
finally:
venv.close()
def train(
_run,
_seed: int,
env_name: str,
rollout_path: str,
n_expert_demos: Optional[int],
log_dir: str,
init_trainer_kwargs: dict,
total_timesteps: int,
n_episodes_eval: int,
init_tensorboard: bool,
checkpoint_interval: int,
) -> dict:
"""Train an adversarial-network-based imitation learning algorithm.
Plots (turn on using `plot_interval > 0`):
- Plot discriminator loss during discriminator training steps in blue and
discriminator loss during generator training steps in red.
- Plot the performance of the generator policy versus the performance of
a random policy. Also plot the performance of an expert policy if that is
provided in the arguments.
Checkpoints:
- DiscrimNets are saved to f"{log_dir}/checkpoints/{step}/discrim/",
where step is either the training epoch or "final".
- Generator policies are saved to
f"{log_dir}/checkpoints/{step}/gen_policy/".
Args:
_seed: Random seed.
env_name: The environment to train in.
rollout_path: Path to pickle containing list of Trajectories. Used as
expert demonstrations.
n_expert_demos: The number of expert trajectories to actually use
after loading them from `rollout_path`.
If None, then use all available trajectories.
If `n_expert_demos` is an `int`, then use exactly `n_expert_demos`
trajectories, erroring if there aren't enough trajectories. If there are
surplus trajectories, then use the
first `n_expert_demos` trajectories and drop the rest.
log_dir: Directory to save models and other logging to.
init_trainer_kwargs: Keyword arguments passed to `init_trainer`,
used to initialize the trainer.
total_timesteps: The number of transitions to sample from the environment
during training.
n_episodes_eval: The number of episodes to average over when calculating
the average episode reward of the imitation policy for return.
plot_interval: The number of epochs between each plot. If negative,
then plots are disabled. If zero, then only plot at the end of training.
n_plot_episodes: The number of episodes averaged over when
calculating the average episode reward of a policy for the performance
plots.
extra_episode_data_interval: Usually mean episode rewards are calculated
immediately before every plot. Set this parameter to a nonnegative number
to also add episode reward data points every
`extra_episodes_data_interval` epochs.
show_plots: Figures are always saved to `f"{log_dir}/plots/*.png"`. If
`show_plots` is True, then also show plots as they are created.
init_tensorboard: If True, then write tensorboard logs to `{log_dir}/sb_tb`.
checkpoint_interval: Save the discriminator and generator models every
`checkpoint_interval` epochs and after training is complete. If 0,
then only save weights after training is complete. If <0, then don't
save weights at all.
Returns:
A dictionary with two keys. "imit_stats" gives the return value of
`rollout_stats()` on rollouts test-reward-wrapped
environment, using the final policy (remember that the ground-truth reward
can be recovered from the "monitor_return" key). "expert_stats" gives the
return value of `rollout_stats()` on the expert demonstrations loaded from
`rollout_path`.
"""
total_timesteps = int(total_timesteps)
tf.logging.info("Logging to %s", log_dir)
os.makedirs(log_dir, exist_ok=True)
sacred_util.build_sacred_symlink(log_dir, _run)
# Calculate stats for expert rollouts. Used for plot and return value.
expert_trajs = types.load(rollout_path)
if n_expert_demos is not None:
assert len(expert_trajs) >= n_expert_demos
expert_trajs = expert_trajs[:n_expert_demos]
expert_stats = rollout.rollout_stats(expert_trajs)
with networks.make_session():
if init_tensorboard:
sb_tensorboard_dir = osp.join(log_dir, "sb_tb")
kwargs = init_trainer_kwargs
kwargs["init_rl_kwargs"] = kwargs.get("init_rl_kwargs", {})
kwargs["init_rl_kwargs"]["tensorboard_log"] = sb_tensorboard_dir
trainer = init_trainer(env_name,
expert_trajs,
seed=_seed,
log_dir=log_dir,
**init_trainer_kwargs)
def callback(epoch):
if checkpoint_interval > 0 and epoch % checkpoint_interval == 0:
save(trainer,
os.path.join(log_dir, "checkpoints", f"{epoch:05d}"))
trainer.train(total_timesteps, callback)
# Save final artifacts.
if checkpoint_interval >= 0:
save(trainer, os.path.join(log_dir, "checkpoints", "final"))
# Final evaluation of imitation policy.
results = {}
sample_until_eval = rollout.min_episodes(n_episodes_eval)
trajs = rollout.generate_trajectories(trainer.gen_policy,
trainer.venv_test,
sample_until=sample_until_eval)
results["imit_stats"] = rollout.rollout_stats(trajs)
results["expert_stats"] = expert_stats
return results