Tianshou/tianshou/trainer/offpolicy.py
danagi 16d8e9b051
SAC implementation update (#212)
- replace DiagGuassian with Independent(Normal) (pytorch has already supported this)
- detach alpha from autograd
- add value/alpha to result (more informational)
- revert #204 to fix #211

Co-authored-by: Trinkle23897 <463003665@qq.com>
2020-09-12 08:44:50 +08:00

142 lines
6.4 KiB
Python

import time
import tqdm
from torch.utils.tensorboard import SummaryWriter
from typing import Dict, List, Union, Callable, Optional
from tianshou.data import Collector
from tianshou.policy import BasePolicy
from tianshou.utils import tqdm_config, MovAvg
from tianshou.trainer import test_episode, gather_info
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.
stat = {}
start_time = time.time()
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 and 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)