Important Note fastrl==2.* is being developed at fastrl. https://github.com/josiahls/fastrl) is the permanent place for all fastai version 2.0 changes as well as faster/refactored/more stable models. Please go there instead for new information/code.

Fast_rl

This repo is not affiliated with Jeremy Howard or his course which can be found here. We will be using components from the Fastai library for building and training our reinforcement learning (RL) agents.

Our goal is for fast_rl to be make benchmarking easier, inference more efficient, and environment compatibility to be as decoupled as much as possible. This being version 1.0, we still have a lot of work to make RL training itself faster and more efficient. The goals for this repo can be seen in the RoadMap.

An important note is that training can use up a lot of RAM. This will likely be resolved as more models are being added. Likely will be resolved by off loading to storage in the next few versions.

A simple example:

from fast_rl.agents.dqn import create_dqn_model, dqn_learner
from fast_rl.agents.dqn_models import *
from fast_rl.core.agent_core import ExperienceReplay,  GreedyEpsilon
from fast_rl.core.data_block import MDPDataBunch
from fast_rl.core.metrics import RewardMetric, EpsilonMetric

memory = ExperienceReplay(memory_size=1000000, reduce_ram=True)
explore = GreedyEpsilon(epsilon_start=1, epsilon_end=0.1, decay=0.001)
data = MDPDataBunch.from_env('CartPole-v1', render='human', bs=64, add_valid=False)
model = create_dqn_model(data=data, base_arch=FixedTargetDQNModule, lr=0.001, layers=[32,32])
learn = dqn_learner(data, model, memory=memory, exploration_method=explore, copy_over_frequency=300,
                    callback_fns=[RewardMetric, EpsilonMetric])
learn.fit(450)

More complex examples might involve running an RL agent multiple times, generating episode snapshots as gifs, grouping reward plots, and finally showing the best and worst runs in a single graph.

from fastai.basic_data import DatasetType
from fast_rl.agents.dqn import create_dqn_model, dqn_learner
from fast_rl.agents.dqn_models import *
from fast_rl.core.agent_core import ExperienceReplay, GreedyEpsilon
from fast_rl.core.data_block import MDPDataBunch
from fast_rl.core.metrics import RewardMetric, EpsilonMetric
from fast_rl.core.train import GroupAgentInterpretation, AgentInterpretation

group_interp = GroupAgentInterpretation()
for i in range(5):
	memory = ExperienceReplay(memory_size=1000000, reduce_ram=True)
	explore = GreedyEpsilon(epsilon_start=1, epsilon_end=0.1, decay=0.001)
	data = MDPDataBunch.from_env('CartPole-v1', render='human', bs=64, add_valid=False)
	model = create_dqn_model(data=data, base_arch=FixedTargetDQNModule, lr=0.001, layers=[32,32])
	learn = dqn_learner(data, model, memory=memory, exploration_method=explore, copy_over_frequency=300,
						callback_fns=[RewardMetric, EpsilonMetric])
	learn.fit(450)

	interp=AgentInterpretation(learn, ds_type=DatasetType.Train)
	interp.plot_rewards(cumulative=True, per_episode=True, group_name='cartpole_experience_example')
	group_interp.add_interpretation(interp)
	group_interp.to_pickle(f'{learn.model.name.lower()}/', f'{learn.model.name.lower()}')
	for g in interp.generate_gif(): g.write(f'{learn.model.name.lower()}')
group_interp.plot_reward_bounds(per_episode=True, smooth_groups=10)

More examples can be found in docs_src and the actual code being run for generating gifs can be found in tests in either test_dqn.py or test_ddpg.py.

As a note, here is a run down of existing RL frameworks:

• Intel Coach
• Tensor Force
• OpenAI Baselines
• Tensorflow Agents
• KerasRL

However there are also frameworks in PyTorch:

• Horizon
• DeepRL
• Spinning Up

Installation

fastai (semi-optional)
Install Fastai or if you are using Anaconda (which is a good idea to use Anaconda) you can do:
conda install -c pytorch -c fastai fastai

fast_rl
Fastai will be installed if it does not exist. If it does exist, the versioning should be repaired by the the setup.py. pip install fastai

Installation (Optional)

OpenAI all gyms:
pip install gym[all]

Mazes:
git clone https://github.com/MattChanTK/gym-maze.git
cd gym-maze
python setup.py install

Installation Dev (Optional)

git clone https://github.com/josiahls/fast-reinforcement-learning.git
cd fast-reinforcement-learning
python setup.py install

Installation Issues

Many issues will likely fall under fastai installation issues.

Any other issues are likely environment related. It is important to note that Python 3.7 is not being tested due to an issue with Pyglet and gym do not working. This issue will not stop you from training models, however this might impact using OpenAI environments.

RoadMap

• Working on 1.0.0 Base version is completed with working model visualizations proving performance / expected failure. At this point, all models should have guaranteed environments they should succeed in.
• 1.1.0 Working on More Traditional RL models
  • Working on Add PPO
  • Working on Add TRPO
  • Add D4PG
  • Add A2C
  • Add A3C
• 1.2.0 HRL models Possibly might change version to 2.0 depending on SMDP issues
  • Add SMDP
  • Add Goal oriented MDPs. Will Require a new "Step"
  • Add FeUdal Network
  • Add storage based DataBunch memory management. This can prevent RAM from being used up by episode image frames that may or may not serve any use to the agent, but only for logging.
• 1.3.0
  • Add HAC
  • Add MAXQ
  • Add HIRO
• 1.4.0
  • Add h-DQN
  • Add Modulated Policy Hierarchies
  • Add Meta Learning Shared Hierarchies
• 1.5.0
  • Add STRategic Attentive Writer (STRAW)
  • Add H-DRLN
  • Add Abstract Markov Decision Process (AMDP)
  • Add conda integration so that installation can be truly one step.
• 1.6.0 HRL Options models Possibly will already be implemented in a previous model
  • Options augmentation to DQN based models
  • Options augmentation to actor critic models
  • Options augmentation to async actor critic models
• 1.8.0 HRL Skills
  • Skills augmentation to DQN based models
  • Skills augmentation to actor critic models
  • Skills augmentation to async actor critic models
• 1.9.0
• 2.0.0 Add PyBullet Fetch Environments
  • 2.0.0 Not part of this repo, however the envs need to subclass the OpenAI gym.GoalEnv
  • 2.0.0 Add HER

Contribution

Following fastai's guidelines would be desirable: Guidelines

While we hope that model additions will be added smoothly. All models will only be dependent on core.layers.py. As time goes on, the model architecture will overall improve (we are and while continue to be still figuring things out).

Style

Since fastai uses a different style from traditional PEP-8, we will be following Style and Abbreviations. Also we will use RL specific abbr.

	Concept	Abbr.	Combination Examples
RL	State	st
	Action	acn
	Bounds	bb	Same as Bounding Box

Examples

Reward Graphs

	Model
	DQN
	Dueling DQN
	Double DQN
	DDDQN
	Fixed Target DQN
	DQN
	Dueling DQN
	Double DQN
	DDDQN
	Fixed Target DQN
	DDPG
	DDPG
	DDPG

Agent Stages

Model	Gif(Early)	Gif(Mid)	Gif(Late)
DDPG+PER
DoubleDueling+ER
DoubleDQN+ER
DuelingDQN+ER
DoubleDueling+PER
DQN+ER
DuelingDQN+PER
DQN+PER
DoubleDQN+PER
DDPG+PER
DDPG+ER
DQN+PER
FixedTargetDQN+ER
DQN+ER
FixedTargetDQN+PER
DoubleDQN+ER
DoubleDQN+PER
DuelingDQN+ER
DoubleDueling+PER
DuelingDQN+PER
DoubleDueling+ER
DDPG+ER
DDPG+PER