def offline_trainer(
policy: BasePolicy,
buffer: ReplayBuffer,
test_collector: Collector,
max_epoch: int,
update_per_epoch: int,
episode_per_test: int,
batch_size: int,
test_fn: Optional[Callable[[int, Optional[int]], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
reward_metric: Optional[Callable[[np.ndarray], np.ndarray]] = None,
logger: BaseLogger = LazyLogger(),
verbose: bool = True,
) -> Dict[str, Union[float, str]]:
"""A wrapper for offline trainer procedure.
The "step" in offline trainer means a gradient step.
:param policy: an instance of the :class:`~tianshou.policy.BasePolicy` class.
:param Collector test_collector: the collector used for testing.
:param int max_epoch: the maximum number of epochs for training. The training
process might be finished before reaching ``max_epoch`` if ``stop_fn`` is set.
:param int update_per_epoch: the number of policy network updates, so-called
gradient steps, per epoch.
:param episode_per_test: the number of episodes for one policy evaluation.
:param int batch_size: the batch size of sample data, which is going to feed in
the policy network.
:param function test_fn: a hook called at the beginning of testing in each epoch.
It can be used to perform custom additional operations, with the signature ``f(
num_epoch: int, step_idx: int) -> None``.
:param function save_fn: a hook called when the undiscounted average mean reward in
evaluation phase gets better, with the signature ``f(policy: BasePolicy) ->
None``.
:param function stop_fn: a function with signature ``f(mean_rewards: float) ->
bool``, receives the average undiscounted returns of the testing result,
returns a boolean which indicates whether reaching the goal.
:param function reward_metric: a function with signature ``f(rewards: np.ndarray
with shape (num_episode, agent_num)) -> np.ndarray with shape (num_episode,)``,
used in multi-agent RL. We need to return a single scalar for each episode's
result to monitor training in the multi-agent RL setting. This function
specifies what is the desired metric, e.g., the reward of agent 1 or the
average reward over all agents.
:param BaseLogger logger: A logger that logs statistics during updating/testing.
Default to a logger that doesn't log anything.
:param bool verbose: whether to print the information. Default to True.
:return: See :func:`~tianshou.trainer.gather_info`.
"""
gradient_step = 0
stat: Dict[str, MovAvg] = defaultdict(MovAvg)
start_time = time.time()
test_collector.reset_stat()
test_result = test_episode(policy, test_collector, test_fn, 0,
episode_per_test, logger, gradient_step,
reward_metric)
best_epoch = 0
best_reward, best_reward_std = test_result["rew"], test_result["rew_std"]
for epoch in range(1, 1 + max_epoch):
policy.train()
with tqdm.trange(update_per_epoch,
desc=f"Epoch #{epoch}",
**tqdm_config) as t:
for i in t:
gradient_step += 1
losses = policy.update(batch_size, buffer)
data = {"gradient_step": str(gradient_step)}
for k in losses.keys():
stat[k].add(losses[k])
losses[k] = stat[k].get()
data[k] = f"{losses[k]:.3f}"
logger.log_update_data(losses, gradient_step)
t.set_postfix(**data)
# test
test_result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, logger, gradient_step,
reward_metric)
rew, rew_std = test_result["rew"], test_result["rew_std"]
if best_epoch == -1 or best_reward < rew:
best_reward, best_reward_std = rew, rew_std
best_epoch = epoch
if save_fn:
save_fn(policy)
if verbose:
print(
f"Epoch #{epoch}: test_reward: {rew:.6f} ± {rew_std:.6f}, best_rew"
f"ard: {best_reward:.6f} ± {best_reward_std:.6f} in #{best_epoch}"
)
if stop_fn and stop_fn(best_reward):
break
return gather_info(start_time, None, test_collector, best_reward,
best_reward_std)
def onpolicy_trainer(
policy: BasePolicy,
train_collector: Collector,
test_collector: Collector,
max_epoch: int,
step_per_epoch: int,
repeat_per_collect: int,
episode_per_test: int,
batch_size: int,
step_per_collect: Optional[int] = None,
episode_per_collect: Optional[int] = None,
train_fn: Optional[Callable[[int, int], None]] = None,
test_fn: Optional[Callable[[int, Optional[int]], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
reward_metric: Optional[Callable[[np.ndarray], np.ndarray]] = None,
logger: BaseLogger = LazyLogger(),
verbose: bool = True,
test_in_train: bool = True,
) -> Dict[str, Union[float, str]]:
"""A wrapper for on-policy trainer procedure.
The "step" in trainer means an environment step (a.k.a. transition).
:param policy: an instance of the :class:`~tianshou.policy.BasePolicy` class.
:param Collector train_collector: the collector used for training.
:param Collector test_collector: the collector used for testing.
:param int max_epoch: the maximum number of epochs for training. The training
process might be finished before reaching ``max_epoch`` if ``stop_fn`` is set.
:param int step_per_epoch: the number of transitions collected per epoch.
:param int repeat_per_collect: the number of repeat time for policy learning, for
example, set it to 2 means the policy needs to learn each given batch data
twice.
:param int episode_per_test: the number of episodes for one policy evaluation.
:param int batch_size: the batch size of sample data, which is going to feed in the
policy network.
:param int step_per_collect: the number of transitions the collector would collect
before the network update, i.e., trainer will collect "step_per_collect"
transitions and do some policy network update repeatly in each epoch.
:param int episode_per_collect: the number of episodes the collector would collect
before the network update, i.e., trainer will collect "episode_per_collect"
episodes and do some policy network update repeatly in each epoch.
:param function train_fn: a hook called at the beginning of training in each epoch.
It can be used to perform custom additional operations, with the signature ``f(
num_epoch: int, step_idx: int) -> None``.
:param function test_fn: a hook called at the beginning of testing in each epoch.
It can be used to perform custom additional operations, with the signature ``f(
num_epoch: int, step_idx: int) -> None``.
:param function save_fn: a hook called when the undiscounted average mean reward in
evaluation phase gets better, with the signature ``f(policy: BasePolicy) ->
None``.
:param function stop_fn: a function with signature ``f(mean_rewards: float) ->
bool``, receives the average undiscounted returns of the testing result,
returns a boolean which indicates whether reaching the goal.
:param function reward_metric: a function with signature ``f(rewards: np.ndarray
with shape (num_episode, agent_num)) -> np.ndarray with shape (num_episode,)``,
used in multi-agent RL. We need to return a single scalar for each episode's
result to monitor training in the multi-agent RL setting. This function
specifies what is the desired metric, e.g., the reward of agent 1 or the
average reward over all agents.
:param BaseLogger logger: A logger that logs statistics during
training/testing/updating. Default to a logger that doesn't log anything.
:param bool verbose: whether to print the information. Default to True.
:param bool test_in_train: whether to test in the training phase. Default to True.
:return: See :func:`~tianshou.trainer.gather_info`.
.. note::
Only either one of step_per_collect and episode_per_collect can be specified.
"""
env_step, gradient_step = 0, 0
last_rew, last_len = 0.0, 0
stat: Dict[str, MovAvg] = defaultdict(MovAvg)
start_time = time.time()
train_collector.reset_stat()
test_collector.reset_stat()
test_in_train = test_in_train and train_collector.policy == policy
test_result = test_episode(policy, test_collector, test_fn, 0,
episode_per_test, logger, env_step,
reward_metric)
best_epoch = 0
best_reward, best_reward_std = test_result["rew"], test_result["rew_std"]
for epoch in range(1, 1 + max_epoch):
# train
policy.train()
with tqdm.tqdm(total=step_per_epoch,
desc=f"Epoch #{epoch}",
**tqdm_config) as t:
while t.n < t.total:
if train_fn:
train_fn(epoch, env_step)
result = train_collector.collect(n_step=step_per_collect,
n_episode=episode_per_collect)
if reward_metric:
result["rews"] = reward_metric(result["rews"])
env_step += int(result["n/st"])
t.update(result["n/st"])
logger.log_train_data(result, env_step)
last_rew = result['rew'] if 'rew' in result else last_rew
last_len = result['len'] if 'len' in result else last_len
data = {
"env_step": str(env_step),
"rew": f"{last_rew:.2f}",
"len": str(int(last_len)),
"n/ep": str(int(result["n/ep"])),
"n/st": str(int(result["n/st"])),
}
if test_in_train and stop_fn and stop_fn(result["rew"]):
test_result = test_episode(policy, test_collector, test_fn,
epoch, episode_per_test, logger,
env_step)
if stop_fn(test_result["rew"]):
if save_fn:
save_fn(policy)
t.set_postfix(**data)
return gather_info(start_time, train_collector,
test_collector, test_result["rew"],
test_result["rew_std"])
else:
policy.train()
losses = policy.update(0,
train_collector.buffer,
batch_size=batch_size,
repeat=repeat_per_collect)
train_collector.reset_buffer()
step = max(
[1] +
[len(v) for v in losses.values() if isinstance(v, list)])
gradient_step += step
for k in losses.keys():
stat[k].add(losses[k])
losses[k] = stat[k].get()
data[k] = f"{losses[k]:.3f}"
logger.log_update_data(losses, gradient_step)
t.set_postfix(**data)
if t.n <= t.total:
t.update()
# test
test_result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, logger, env_step)
rew, rew_std = test_result["rew"], test_result["rew_std"]
if best_epoch == -1 or best_reward < rew:
best_reward, best_reward_std = rew, rew_std
best_epoch = epoch
if save_fn:
save_fn(policy)
if verbose:
print(
f"Epoch #{epoch}: test_reward: {rew:.6f} ± {rew_std:.6f}, best_rew"
f"ard: {best_reward:.6f} ± {best_reward_std:.6f} in #{best_epoch}"
)
if stop_fn and stop_fn(best_reward):
break
return gather_info(start_time, train_collector, test_collector,
best_reward, best_reward_std)
def onpolicy_trainer(
policy: BasePolicy,
train_collector: Collector,
test_collector: Collector,
max_epoch: int,
step_per_epoch: int,
collect_per_step: int,
repeat_per_collect: int,
episode_per_test: Union[int, List[int]],
batch_size: int,
train_fn: Optional[Callable[[int, int], None]] = None,
test_fn: Optional[Callable[[int, Optional[int]], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
writer: Optional[SummaryWriter] = None,
log_interval: int = 1,
verbose: bool = True,
test_in_train: bool = True,
) -> Dict[str, Union[float, str]]:
"""A wrapper for on-policy trainer procedure.
The "step" in trainer means a policy network update.
:param policy: an instance of the :class:`~tianshou.policy.BasePolicy`
class.
:param train_collector: the collector used for training.
:type train_collector: :class:`~tianshou.data.Collector`
:param test_collector: the collector used for testing.
:type test_collector: :class:`~tianshou.data.Collector`
:param int max_epoch: the maximum of epochs for training. The training
process might be finished before reaching the ``max_epoch``.
:param int step_per_epoch: the number of step for updating policy network
in one epoch.
:param int collect_per_step: the number of episodes the collector would
collect before the network update. In other words, collect some
episodes and do one policy network update.
:param int repeat_per_collect: the number of repeat time for policy
learning, for example, set it to 2 means the policy needs to learn each
given batch data twice.
:param episode_per_test: the number of episodes for one policy evaluation.
:type episode_per_test: int or list of ints
:param int batch_size: the batch size of sample data, which is going to
feed in the policy network.
:param function train_fn: a function receives the current number of epoch
and step index, and performs some operations at the beginning of
training in this poch.
:param function test_fn: a function receives the current number of epoch
and step index, and performs some operations at the beginning of
testing in this epoch.
:param function save_fn: a function for saving policy when the undiscounted
average mean reward in evaluation phase gets better.
:param function stop_fn: a function receives the average undiscounted
returns of the testing result, return a boolean which indicates whether
reaching the goal.
:param torch.utils.tensorboard.SummaryWriter writer: a TensorBoard
SummaryWriter.
:param int log_interval: the log interval of the writer.
:param bool verbose: whether to print the information.
:param bool test_in_train: whether to test in the training phase.
:return: See :func:`~tianshou.trainer.gather_info`.
"""
env_step, gradient_step = 0, 0
best_epoch, best_reward, best_reward_std = -1, -1.0, 0.0
stat: Dict[str, MovAvg] = {}
start_time = time.time()
train_collector.reset_stat()
test_collector.reset_stat()
test_in_train = test_in_train and train_collector.policy == policy
for epoch in range(1, 1 + max_epoch):
# train
policy.train()
with tqdm.tqdm(
total=step_per_epoch, desc=f"Epoch #{epoch}", **tqdm_config
) as t:
while t.n < t.total:
if train_fn:
train_fn(epoch, env_step)
result = train_collector.collect(n_episode=collect_per_step)
env_step += int(result["n/st"])
data = {
"env_step": str(env_step),
"rew": f"{result['rew']:.2f}",
"len": str(int(result["len"])),
"n/ep": str(int(result["n/ep"])),
"n/st": str(int(result["n/st"])),
"v/ep": f"{result['v/ep']:.2f}",
"v/st": f"{result['v/st']:.2f}",
}
if writer and env_step % log_interval == 0:
for k in result.keys():
writer.add_scalar(
"train/" + k, result[k], global_step=env_step)
if test_in_train and stop_fn and stop_fn(result["rew"]):
test_result = test_episode(
policy, test_collector, test_fn,
epoch, episode_per_test, writer, env_step)
if stop_fn(test_result["rew"]):
if save_fn:
save_fn(policy)
for k in result.keys():
data[k] = f"{result[k]:.2f}"
t.set_postfix(**data)
return gather_info(
start_time, train_collector, test_collector,
test_result["rew"], test_result["rew_std"])
else:
policy.train()
losses = policy.update(
0, train_collector.buffer,
batch_size=batch_size, repeat=repeat_per_collect)
train_collector.reset_buffer()
step = max([1] + [
len(v) for v in losses.values() if isinstance(v, list)])
gradient_step += step
for k in losses.keys():
if stat.get(k) is None:
stat[k] = MovAvg()
stat[k].add(losses[k])
data[k] = f"{stat[k].get():.6f}"
if writer and gradient_step % log_interval == 0:
writer.add_scalar(
k, stat[k].get(), global_step=gradient_step)
t.update(step)
t.set_postfix(**data)
if t.n <= t.total:
t.update()
# test
result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, writer, env_step)
if best_epoch == -1 or best_reward < result["rew"]:
best_reward, best_reward_std = result["rew"], result["rew_std"]
best_epoch = epoch
if save_fn:
save_fn(policy)
if verbose:
print(f"Epoch #{epoch}: test_reward: {result['rew']:.6f} ± "
f"{result['rew_std']:.6f}, best_reward: {best_reward:.6f} ± "
f"{best_reward_std:.6f} in #{best_epoch}")
if stop_fn and stop_fn(best_reward):
break
return gather_info(start_time, train_collector, test_collector,
best_reward, best_reward_std)
def onpolicy_trainer(
policy: BasePolicy,
train_collector: Collector,
test_collector: Collector,
max_epoch: int,
frame_per_epoch: int,
collect_per_step: int,
repeat_per_collect: int,
episode_per_test: Union[int, Sequence[int]],
batch_size: int,
train_fn: Optional[Callable[[int, int], None]] = None,
test_fn: Optional[Callable[[int, Optional[int]], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
writer: Optional[SummaryWriter] = None,
log_interval: int = 1,
verbose: bool = True,
test_in_train: bool = True,
**kwargs) -> Dict[str, Union[float, str]]:
"""Slightly modified Tianshou `onpolicy_trainer` original method to enable
to define the maximum number of training steps instead of number of
episodes, for consistency with other learning frameworks.
"""
global_step = 0
best_epoch, best_reward = -1, -1.0
stat: Dict[str, MovAvg] = {}
start_time = time.time()
train_collector.reset_stat()
test_collector.reset_stat()
test_in_train = test_in_train and train_collector.policy == policy
for epoch in range(1, 1 + max_epoch):
# train
policy.train()
with tqdm.tqdm(
total=frame_per_epoch, desc=f"Epoch #{epoch}", **tqdm_config
) as t:
while t.n < t.total:
if train_fn:
train_fn(epoch, global_step)
result = train_collector.collect(n_step=collect_per_step)
data = {}
if test_in_train and stop_fn and stop_fn(result["rew"]):
test_result = test_episode(
policy, test_collector, test_fn,
epoch, episode_per_test, writer, global_step)
if stop_fn(test_result["rew"]):
if save_fn:
save_fn(policy)
for k in result.keys():
data[k] = f"{result[k]:.2f}"
t.set_postfix(**data)
return gather_info(
start_time, train_collector, test_collector,
test_result["rew"])
else:
policy.train()
losses = policy.update(
0, train_collector.buffer,
batch_size=batch_size, repeat=repeat_per_collect)
train_collector.reset_buffer()
step = 1
for v in losses.values():
if isinstance(v, (list, tuple)):
step = max(step, len(v))
global_step += step * collect_per_step
for k in result.keys():
data[k] = f"{result[k]:.2f}"
if writer and global_step % log_interval == 0:
writer.add_scalar(
"train/" + k, result[k], global_step=global_step)
for k in losses.keys():
if stat.get(k) is None:
stat[k] = MovAvg()
stat[k].add(losses[k])
data[k] = f"{stat[k].get():.6f}"
if writer and global_step % log_interval == 0:
writer.add_scalar(
k, stat[k].get(), global_step=global_step)
t.update(collect_per_step)
t.set_postfix(**data)
if t.n <= t.total:
t.update()
# test
result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, writer, global_step)
if best_epoch == -1 or best_reward < result["rew"]:
best_reward = result["rew"]
best_epoch = epoch
if save_fn:
save_fn(policy)
if verbose:
print(f"Epoch #{epoch}: test_reward: {result['rew']:.6f}, "
f"best_reward: {best_reward:.6f} in #{best_epoch}")
if stop_fn and stop_fn(best_reward):
break
return gather_info(
start_time, train_collector, test_collector, best_reward)
def offpolicy_trainer(
policy: BasePolicy,
train_collector: Collector,
test_collector: Collector,
max_epoch: int,
step_per_epoch: int,
collect_per_step: int,
episode_per_test: Union[int, List[int]],
batch_size: int,
update_per_step: int = 1,
train_fn: Optional[Callable[[int], None]] = None,
test_fn: Optional[Callable[[int], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
writer: Optional[SummaryWriter] = None,
log_interval: int = 1,
verbose: bool = True,
test_in_train: bool = True,
) -> Dict[str, Union[float, str]]:
"""A wrapper for off-policy trainer procedure.
The "step" in trainer means a policy network update.
:param policy: an instance of the :class:`~tianshou.policy.BasePolicy`
class.
:param train_collector: the collector used for training.
:type train_collector: :class:`~tianshou.data.Collector`
:param test_collector: the collector used for testing.
:type test_collector: :class:`~tianshou.data.Collector`
:param int max_epoch: the maximum of epochs for training. The training
process might be finished before reaching the ``max_epoch``.
:param int step_per_epoch: the number of step for updating policy network
in one epoch.
:param int collect_per_step: the number of frames the collector would
collect before the network update. In other words, collect some frames
and do some policy network update.
:param episode_per_test: the number of episodes for one policy evaluation.
:param int batch_size: the batch size of sample data, which is going to
feed in the policy network.
:param int update_per_step: the number of times the policy network would
be updated after frames are collected, for example, set it to 256 means
it updates policy 256 times once after ``collect_per_step`` frames are
collected.
:param function train_fn: a function receives the current number of epoch
index and performs some operations at the beginning of training in this
epoch.
:param function test_fn: a function receives the current number of epoch
index and performs some operations at the beginning of testing in this
epoch.
:param function save_fn: a function for saving policy when the undiscounted
average mean reward in evaluation phase gets better.
:param function stop_fn: a function receives the average undiscounted
returns of the testing result, return a boolean which indicates whether
reaching the goal.
:param torch.utils.tensorboard.SummaryWriter writer: a TensorBoard
SummaryWriter.
:param int log_interval: the log interval of the writer.
:param bool verbose: whether to print the information.
:param bool test_in_train: whether to test in the training phase.
:return: See :func:`~tianshou.trainer.gather_info`.
"""
global_step = 0
best_epoch, best_reward = -1, -1.0
stat: Dict[str, MovAvg] = {}
start_time = time.time()
train_collector.reset_stat()
test_collector.reset_stat()
test_in_train = test_in_train and train_collector.policy == policy
for epoch in range(1, 1 + max_epoch):
# train
policy.train()
if train_fn:
train_fn(epoch)
with tqdm.tqdm(total=step_per_epoch,
desc=f"Epoch #{epoch}",
**tqdm_config) as t:
while t.n < t.total:
result = train_collector.collect(n_step=collect_per_step)
data = {}
if test_in_train and stop_fn and stop_fn(result["rew"]):
test_result = test_episode(policy, test_collector, test_fn,
epoch, episode_per_test, writer,
global_step)
if stop_fn(test_result["rew"]):
if save_fn:
save_fn(policy)
for k in result.keys():
data[k] = f"{result[k]:.2f}"
t.set_postfix(**data)
return gather_info(start_time, train_collector,
test_collector, test_result["rew"])
else:
policy.train()
if train_fn:
train_fn(epoch)
for i in range(update_per_step * min(
result["n/st"] // collect_per_step, t.total - t.n)):
global_step += collect_per_step
losses = policy.update(batch_size, train_collector.buffer)
for k in result.keys():
data[k] = f"{result[k]:.2f}"
if writer and global_step % log_interval == 0:
writer.add_scalar("train/" + k,
result[k],
global_step=global_step)
for k in losses.keys():
if stat.get(k) is None:
stat[k] = MovAvg()
stat[k].add(losses[k])
data[k] = f"{stat[k].get():.6f}"
if writer and global_step % log_interval == 0:
writer.add_scalar(k,
stat[k].get(),
global_step=global_step)
t.update(1)
t.set_postfix(**data)
if t.n <= t.total:
t.update()
# test
result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, writer, global_step)
if best_epoch == -1 or best_reward < result["rew"]:
best_reward = result["rew"]
best_epoch = epoch
if save_fn:
save_fn(policy)
if verbose:
print(f"Epoch #{epoch}: test_reward: {result['rew']:.6f}, "
f"best_reward: {best_reward:.6f} in #{best_epoch}")
if stop_fn and stop_fn(best_reward):
break
return gather_info(start_time, train_collector, test_collector,
best_reward)
def offpolicy_trainer(
policy: BasePolicy,
train_collector: Collector,
test_collector: Collector,
max_epoch: int,
step_per_epoch: int,
step_per_collect: int,
episode_per_test: int,
batch_size: int,
update_per_step: Union[int, float] = 1,
train_fn: Optional[Callable[[int, int], None]] = None,
test_fn: Optional[Callable[[int, Optional[int]], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
save_checkpoint_fn: Optional[Callable[[int, int, int], None]] = None,
resume_from_log: bool = False,
reward_metric: Optional[Callable[[np.ndarray], np.ndarray]] = None,
logger: BaseLogger = LazyLogger(),
verbose: bool = True,
test_in_train: bool = True,
) -> Dict[str, Union[float, str]]:
"""A wrapper for off-policy trainer procedure.
The "step" in trainer means an environment step (a.k.a. transition).
:param policy: an instance of the :class:`~tianshou.policy.BasePolicy` class.
:param Collector train_collector: the collector used for training.
:param Collector test_collector: the collector used for testing.
:param int max_epoch: the maximum number of epochs for training. The training
process might be finished before reaching ``max_epoch`` if ``stop_fn`` is set.
:param int step_per_epoch: the number of transitions collected per epoch.
:param int step_per_collect: the number of transitions the collector would collect
before the network update, i.e., trainer will collect "step_per_collect"
transitions and do some policy network update repeatly in each epoch.
:param episode_per_test: the number of episodes for one policy evaluation.
:param int batch_size: the batch size of sample data, which is going to feed in the
policy network.
:param int/float update_per_step: the number of times the policy network would be
updated per transition after (step_per_collect) transitions are collected,
e.g., if update_per_step set to 0.3, and step_per_collect is 256, policy will
be updated round(256 * 0.3 = 76.8) = 77 times after 256 transitions are
collected by the collector. Default to 1.
:param function train_fn: a hook called at the beginning of training in each epoch.
It can be used to perform custom additional operations, with the signature ``f(
num_epoch: int, step_idx: int) -> None``.
:param function test_fn: a hook called at the beginning of testing in each epoch.
It can be used to perform custom additional operations, with the signature ``f(
num_epoch: int, step_idx: int) -> None``.
:param function save_fn: a hook called when the undiscounted average mean reward in
evaluation phase gets better, with the signature ``f(policy: BasePolicy) ->
None``.
:param function save_checkpoint_fn: a function to save training process, with the
signature ``f(epoch: int, env_step: int, gradient_step: int) -> None``; you can
save whatever you want.
:param bool resume_from_log: resume env_step/gradient_step and other metadata from
existing tensorboard log. Default to False.
:param function stop_fn: a function with signature ``f(mean_rewards: float) ->
bool``, receives the average undiscounted returns of the testing result,
returns a boolean which indicates whether reaching the goal.
:param function reward_metric: a function with signature ``f(rewards: np.ndarray
with shape (num_episode, agent_num)) -> np.ndarray with shape (num_episode,)``,
used in multi-agent RL. We need to return a single scalar for each episode's
result to monitor training in the multi-agent RL setting. This function
specifies what is the desired metric, e.g., the reward of agent 1 or the
average reward over all agents.
:param BaseLogger logger: A logger that logs statistics during
training/testing/updating. Default to a logger that doesn't log anything.
:param bool verbose: whether to print the information. Default to True.
:param bool test_in_train: whether to test in the training phase. Default to True.
:return: See :func:`~tianshou.trainer.gather_info`.
"""
if save_fn:
warnings.warn("Please consider using save_checkpoint_fn instead of save_fn.")
start_epoch, env_step, gradient_step = 0, 0, 0
if resume_from_log:
start_epoch, env_step, gradient_step = logger.restore_data()
last_rew, last_len = 0.0, 0
stat: Dict[str, MovAvg] = defaultdict(MovAvg)
start_time = time.time()
train_collector.reset_stat()
test_collector.reset_stat()
test_in_train = test_in_train and train_collector.policy == policy
test_result = test_episode(policy, test_collector, test_fn, start_epoch,
episode_per_test, logger, env_step, reward_metric)
best_epoch = start_epoch
best_reward, best_reward_std = test_result["rew"], test_result["rew_std"]
for epoch in range(1 + start_epoch, 1 + max_epoch):
# train
policy.train()
with tqdm.tqdm(
total=step_per_epoch, desc=f"Epoch #{epoch}", **tqdm_config
) as t:
while t.n < t.total:
if train_fn:
train_fn(epoch, env_step)
result = train_collector.collect(n_step=step_per_collect)
if result["n/ep"] > 0 and reward_metric:
result["rews"] = reward_metric(result["rews"])
env_step += int(result["n/st"])
t.update(result["n/st"])
logger.log_train_data(result, env_step)
last_rew = result['rew'] if 'rew' in result else last_rew
last_len = result['len'] if 'len' in result else last_len
data = {
"env_step": str(env_step),
"rew": f"{last_rew:.2f}",
"len": str(int(last_len)),
"n/ep": str(int(result["n/ep"])),
"n/st": str(int(result["n/st"])),
}
if result["n/ep"] > 0:
if test_in_train and stop_fn and stop_fn(result["rew"]):
test_result = test_episode(
policy, test_collector, test_fn,
epoch, episode_per_test, logger, env_step)
if stop_fn(test_result["rew"]):
if save_fn:
save_fn(policy)
logger.save_data(
epoch, env_step, gradient_step, save_checkpoint_fn)
t.set_postfix(**data)
return gather_info(
start_time, train_collector, test_collector,
test_result["rew"], test_result["rew_std"])
else:
policy.train()
for i in range(round(update_per_step * result["n/st"])):
gradient_step += 1
losses = policy.update(batch_size, train_collector.buffer)
for k in losses.keys():
stat[k].add(losses[k])
losses[k] = stat[k].get()
data[k] = f"{losses[k]:.3f}"
logger.log_update_data(losses, gradient_step)
t.set_postfix(**data)
if t.n <= t.total:
t.update()
# test
test_result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, logger, env_step, reward_metric)
rew, rew_std = test_result["rew"], test_result["rew_std"]
if best_epoch < 0 or best_reward < rew:
best_epoch, best_reward, best_reward_std = epoch, rew, rew_std
if save_fn:
save_fn(policy)
logger.save_data(epoch, env_step, gradient_step, save_checkpoint_fn)
if verbose:
print(f"Epoch #{epoch}: test_reward: {rew:.6f} ± {rew_std:.6f}, best_rew"
f"ard: {best_reward:.6f} ± {best_reward_std:.6f} in #{best_epoch}")
if stop_fn and stop_fn(best_reward):
break
return gather_info(start_time, train_collector, test_collector,
best_reward, best_reward_std)
def offline_trainer(
policy: BasePolicy,
buffer: ReplayBuffer,
test_collector: Collector,
max_epoch: int,
step_per_epoch: int,
episode_per_test: Union[int, List[int]],
batch_size: int,
test_fn: Optional[Callable[[int, Optional[int]], None]] = None,
stop_fn: Optional[Callable[[float], bool]] = None,
save_fn: Optional[Callable[[BasePolicy], None]] = None,
writer: Optional[SummaryWriter] = None,
log_interval: int = 1,
verbose: bool = True,
) -> Dict[str, Union[float, str]]:
"""A wrapper for offline trainer procedure.
The "step" in trainer means a policy network update.
:param policy: an instance of the :class:`~tianshou.policy.BasePolicy`
class.
:param test_collector: the collector used for testing.
:type test_collector: :class:`~tianshou.data.Collector`
:param int max_epoch: the maximum number of epochs for training. The
training process might be finished before reaching the ``max_epoch``.
:param int step_per_epoch: the number of policy network updates, so-called
gradient steps, per epoch.
:param episode_per_test: the number of episodes for one policy evaluation.
:param int batch_size: the batch size of sample data, which is going to
feed in the policy network.
:param function test_fn: a hook called at the beginning of testing in each
epoch. It can be used to perform custom additional operations, with the
signature ``f(num_epoch: int, step_idx: int) -> None``.
:param function save_fn: a hook called when the undiscounted average mean
reward in evaluation phase gets better, with the signature ``f(policy:
BasePolicy) -> None``.
:param function stop_fn: a function with signature ``f(mean_rewards: float)
-> bool``, receives the average undiscounted returns of the testing
result, returns a boolean which indicates whether reaching the goal.
:param torch.utils.tensorboard.SummaryWriter writer: a TensorBoard
SummaryWriter; if None is given, it will not write logs to TensorBoard.
:param int log_interval: the log interval of the writer.
:param bool verbose: whether to print the information.
:return: See :func:`~tianshou.trainer.gather_info`.
"""
gradient_step = 0
best_epoch, best_reward, best_reward_std = -1, -1.0, 0.0
stat: Dict[str, MovAvg] = defaultdict(MovAvg)
start_time = time.time()
test_collector.reset_stat()
for epoch in range(1, 1 + max_epoch):
policy.train()
with tqdm.trange(step_per_epoch, desc=f"Epoch #{epoch}",
**tqdm_config) as t:
for i in t:
gradient_step += 1
losses = policy.update(batch_size, buffer)
data = {"gradient_step": str(gradient_step)}
for k in losses.keys():
stat[k].add(losses[k])
data[k] = f"{stat[k].get():.6f}"
if writer and gradient_step % log_interval == 0:
writer.add_scalar("train/" + k,
stat[k].get(),
global_step=gradient_step)
t.set_postfix(**data)
# test
result = test_episode(policy, test_collector, test_fn, epoch,
episode_per_test, writer, gradient_step)
if best_epoch == -1 or best_reward < result["rew"]:
best_reward, best_reward_std = result["rew"], result["rew_std"]
best_epoch = epoch
if save_fn:
save_fn(policy)
if verbose:
print(f"Epoch #{epoch}: test_reward: {result['rew']:.6f} ± "
f"{result['rew_std']:.6f}, best_reward: {best_reward:.6f} ± "
f"{best_reward_std:.6f} in #{best_epoch}")
if stop_fn and stop_fn(best_reward):
break
return gather_info(start_time, None, test_collector, best_reward,
best_reward_std)
