def eval_policy(env, policy, train_params, obs_params):
n_eval_episodes = train_params.n_evaluation_episodes
max_steps = env._max_episode_steps
tree_depth = obs_params.observation_tree_depth
observation_radius = obs_params.observation_radius
action_dict = dict()
scores = []
completions = []
nb_steps = []
for episode_idx in range(n_eval_episodes):
agent_obs = [None] * env.get_num_agents()
score = 0.0
obs, info = env.reset(regenerate_rail=True, regenerate_schedule=True)
final_step = 0
for step in range(max_steps - 1):
for agent in env.get_agent_handles():
if obs[agent]:
agent_obs[agent] = normalize_observation(
obs[agent],
tree_depth=tree_depth,
observation_radius=observation_radius)
action = 0
if info['action_required'][agent]:
action = policy.act(agent_obs[agent], eps=0.0)
action_dict.update({agent: action})
obs, all_rewards, done, info = env.step(action_dict)
for agent in env.get_agent_handles():
score += all_rewards[agent]
final_step = step
if done['__all__']:
break
normalized_score = score / (max_steps * env.get_num_agents())
scores.append(normalized_score)
tasks_finished = sum(done[idx] for idx in env.get_agent_handles())
completion = tasks_finished / max(1, env.get_num_agents())
completions.append(completion)
nb_steps.append(final_step)
print("\t✅ Eval: score {:.3f} done {:.1f}%".format(
np.mean(scores),
np.mean(completions) * 100.0))
return scores, completions, nb_steps
def act(self, observation, info=None, epsilon=0):
"""
Gets called each step, with a dict of observations for each agent.
Computes dict of actions of all agents
"""
self.time_step += 1
processed_obs = {}
for idx, agent in enumerate(self.env.agents):
if observation[idx] is not None and info is None or info[
'action_required'][idx]:
# Prepare observation
state = observation[idx]
state = normalize_observation(
state,
self.obs_tree_depth,
observation_radius=self.obs_radius)
processed_obs[idx] = state
state = torch.from_numpy(state).float().unsqueeze(0)
state = state.to(self.model.device)
# Predict values of actions
with torch.no_grad():
action_values = self.model(state)
# Epsilon-greedy action selection
if random.random() > epsilon:
action = np.argmax(action_values.cpu().data.numpy())
else:
action = random.choice(np.arange(self.action_size))
self.actions[idx] = action
else:
processed_obs[idx] = None
self.actions[idx] = None
return self.actions, processed_obs
def train_agent(train_params, train_env_params, eval_env_params, obs_params):
# Environment parameters
n_agents = train_env_params.n_agents
x_dim = train_env_params.x_dim
y_dim = train_env_params.y_dim
n_cities = train_env_params.n_cities
max_rails_between_cities = train_env_params.max_rails_between_cities
max_rails_in_city = train_env_params.max_rails_in_city
seed = train_env_params.seed
# Unique ID for this training
now = datetime.now()
training_id = now.strftime('%y%m%d%H%M%S')
# Observation parameters
observation_tree_depth = obs_params.observation_tree_depth
observation_radius = obs_params.observation_radius
observation_max_path_depth = obs_params.observation_max_path_depth
# Training parameters
eps_start = train_params.eps_start
eps_end = train_params.eps_end
eps_decay = train_params.eps_decay
n_episodes = train_params.n_episodes
checkpoint_interval = train_params.checkpoint_interval
n_eval_episodes = train_params.n_evaluation_episodes
restore_replay_buffer = train_params.restore_replay_buffer
save_replay_buffer = train_params.save_replay_buffer
# Set the seeds
random.seed(seed)
np.random.seed(seed)
# Observation builder
predictor = ShortestPathPredictorForRailEnv(observation_max_path_depth)
tree_observation = TreeObsForRailEnv(max_depth=observation_tree_depth,
predictor=predictor)
# Setup the environments
train_env = create_rail_env(train_env_params, tree_observation)
train_env.reset(regenerate_schedule=True, regenerate_rail=True)
eval_env = create_rail_env(eval_env_params, tree_observation)
eval_env.reset(regenerate_schedule=True, regenerate_rail=True)
# Setup renderer
if train_params.render:
env_renderer = RenderTool(train_env, gl="PGL")
# Calculate the state size given the depth of the tree observation and the number of features
n_features_per_node = train_env.obs_builder.observation_dim
n_nodes = sum([np.power(4, i) for i in range(observation_tree_depth + 1)])
state_size = n_features_per_node * n_nodes
# The action space of flatland is 5 discrete actions
action_size = 5
# Max number of steps per episode
# This is the official formula used during evaluations
# See details in flatland.envs.schedule_generators.sparse_schedule_generator
# max_steps = int(4 * 2 * (env.height + env.width + (n_agents / n_cities)))
max_steps = train_env._max_episode_steps
action_count = [0] * action_size
action_dict = dict()
agent_obs = [None] * n_agents
agent_prev_obs = [None] * n_agents
agent_prev_action = [2] * n_agents
update_values = [False] * n_agents
# Smoothed values used as target for hyperparameter tuning
smoothed_normalized_score = -1.0
smoothed_eval_normalized_score = -1.0
smoothed_completion = 0.0
smoothed_eval_completion = 0.0
# Double Dueling DQN policy
policy = DDDQNPolicy(state_size, action_size, train_params)
# Loads existing replay buffer
if restore_replay_buffer:
try:
policy.load_replay_buffer(restore_replay_buffer)
policy.test()
except RuntimeError as e:
print(
"\n🛑 Could't load replay buffer, were the experiences generated using the same tree depth?"
)
print(e)
exit(1)
print("\n💾 Replay buffer status: {}/{} experiences".format(
len(policy.memory.memory), train_params.buffer_size))
hdd = psutil.disk_usage('/')
if save_replay_buffer and (hdd.free / (2**30)) < 500.0:
print(
"⚠️ Careful! Saving replay buffers will quickly consume a lot of disk space. You have {:.2f}gb left."
.format(hdd.free / (2**30)))
# TensorBoard writer
writer = SummaryWriter()
writer.add_hparams(vars(train_params), {})
writer.add_hparams(vars(train_env_params), {})
writer.add_hparams(vars(obs_params), {})
training_timer = Timer()
training_timer.start()
print(
"\n🚉 Training {} trains on {}x{} grid for {} episodes, evaluating on {} episodes every {} episodes. Training id '{}'.\n"
.format(train_env.get_num_agents(), x_dim, y_dim, n_episodes,
n_eval_episodes, checkpoint_interval, training_id))
for episode_idx in range(n_episodes + 1):
step_timer = Timer()
reset_timer = Timer()
learn_timer = Timer()
preproc_timer = Timer()
inference_timer = Timer()
# Reset environment
reset_timer.start()
obs, info = train_env.reset(regenerate_rail=True,
regenerate_schedule=True)
reset_timer.end()
if train_params.render:
env_renderer.set_new_rail()
score = 0
nb_steps = 0
actions_taken = []
# Build initial agent-specific observations
for agent in train_env.get_agent_handles():
if obs[agent]:
agent_obs[agent] = normalize_observation(
obs[agent],
observation_tree_depth,
observation_radius=observation_radius)
agent_prev_obs[agent] = agent_obs[agent].copy()
# Run episode
for step in range(max_steps - 1):
inference_timer.start()
for agent in train_env.get_agent_handles():
if info['action_required'][agent]:
update_values[agent] = True
action = policy.act(agent_obs[agent], eps=eps_start)
action_count[action] += 1
actions_taken.append(action)
else:
# An action is not required if the train hasn't joined the railway network,
# if it already reached its target, or if is currently malfunctioning.
update_values[agent] = False
action = 0
action_dict.update({agent: action})
inference_timer.end()
# Environment step
step_timer.start()
next_obs, all_rewards, done, info = train_env.step(action_dict)
step_timer.end()
# Render an episode at some interval
if train_params.render and episode_idx % checkpoint_interval == 0:
env_renderer.render_env(show=True,
frames=False,
show_observations=False,
show_predictions=False)
# Update replay buffer and train agent
for agent in train_env.get_agent_handles():
if update_values[agent] or done['__all__']:
# Only learn from timesteps where somethings happened
learn_timer.start()
policy.step(agent_prev_obs[agent],
agent_prev_action[agent], all_rewards[agent],
agent_obs[agent], done[agent])
learn_timer.end()
agent_prev_obs[agent] = agent_obs[agent].copy()
agent_prev_action[agent] = action_dict[agent]
# Preprocess the new observations
if next_obs[agent]:
preproc_timer.start()
agent_obs[agent] = normalize_observation(
next_obs[agent],
observation_tree_depth,
observation_radius=observation_radius)
preproc_timer.end()
score += all_rewards[agent]
nb_steps = step
if done['__all__']:
break
# Epsilon decay
eps_start = max(eps_end, eps_decay * eps_start)
# Collect information about training
tasks_finished = sum(done[idx]
for idx in train_env.get_agent_handles())
completion = tasks_finished / max(1, train_env.get_num_agents())
normalized_score = score / (max_steps * train_env.get_num_agents())
action_probs = action_count / np.sum(action_count)
action_count = [1] * action_size
smoothing = 0.99
smoothed_normalized_score = smoothed_normalized_score * smoothing + normalized_score * (
1.0 - smoothing)
smoothed_completion = smoothed_completion * smoothing + completion * (
1.0 - smoothing)
# Print logs
if episode_idx % checkpoint_interval == 0:
torch.save(
policy.qnetwork_local, './checkpoints/' + training_id + '-' +
str(episode_idx) + '.pth')
if save_replay_buffer:
policy.save_replay_buffer('./replay_buffers/' + training_id +
'-' + str(episode_idx) + '.pkl')
if train_params.render:
env_renderer.close_window()
print('\r🚂 Episode {}'
'\t 🏆 Score: {:.3f}'
' Avg: {:.3f}'
'\t 💯 Done: {:.2f}%'
' Avg: {:.2f}%'
'\t 🎲 Epsilon: {:.3f} '
'\t 🔀 Action Probs: {}'.format(episode_idx, normalized_score,
smoothed_normalized_score,
100 * completion,
100 * smoothed_completion,
eps_start,
format_action_prob(action_probs)),
end=" ")
# Evaluate policy and log results at some interval
if episode_idx % checkpoint_interval == 0 and n_eval_episodes > 0:
scores, completions, nb_steps_eval = eval_policy(
eval_env, policy, train_params, obs_params)
writer.add_scalar("evaluation/scores_min", np.min(scores),
episode_idx)
writer.add_scalar("evaluation/scores_max", np.max(scores),
episode_idx)
writer.add_scalar("evaluation/scores_mean", np.mean(scores),
episode_idx)
writer.add_scalar("evaluation/scores_std", np.std(scores),
episode_idx)
writer.add_histogram("evaluation/scores", np.array(scores),
episode_idx)
writer.add_scalar("evaluation/completions_min",
np.min(completions), episode_idx)
writer.add_scalar("evaluation/completions_max",
np.max(completions), episode_idx)
writer.add_scalar("evaluation/completions_mean",
np.mean(completions), episode_idx)
writer.add_scalar("evaluation/completions_std",
np.std(completions), episode_idx)
writer.add_histogram("evaluation/completions",
np.array(completions), episode_idx)
writer.add_scalar("evaluation/nb_steps_min", np.min(nb_steps_eval),
episode_idx)
writer.add_scalar("evaluation/nb_steps_max", np.max(nb_steps_eval),
episode_idx)
writer.add_scalar("evaluation/nb_steps_mean",
np.mean(nb_steps_eval), episode_idx)
writer.add_scalar("evaluation/nb_steps_std", np.std(nb_steps_eval),
episode_idx)
writer.add_histogram("evaluation/nb_steps",
np.array(nb_steps_eval), episode_idx)
smoothing = 0.9
smoothed_eval_normalized_score = smoothed_eval_normalized_score * smoothing + np.mean(
scores) * (1.0 - smoothing)
smoothed_eval_completion = smoothed_eval_completion * smoothing + np.mean(
completions) * (1.0 - smoothing)
writer.add_scalar("evaluation/smoothed_score",
smoothed_eval_normalized_score, episode_idx)
writer.add_scalar("evaluation/smoothed_completion",
smoothed_eval_completion, episode_idx)
# Save logs to tensorboard
writer.add_scalar("training/score", normalized_score, episode_idx)
writer.add_scalar("training/smoothed_score", smoothed_normalized_score,
episode_idx)
writer.add_scalar("training/completion", np.mean(completion),
episode_idx)
writer.add_scalar("training/smoothed_completion",
np.mean(smoothed_completion), episode_idx)
writer.add_scalar("training/nb_steps", nb_steps, episode_idx)
writer.add_histogram("actions/distribution", np.array(actions_taken),
episode_idx)
writer.add_scalar("actions/nothing",
action_probs[RailEnvActions.DO_NOTHING], episode_idx)
writer.add_scalar("actions/left",
action_probs[RailEnvActions.MOVE_LEFT], episode_idx)
writer.add_scalar("actions/forward",
action_probs[RailEnvActions.MOVE_FORWARD],
episode_idx)
writer.add_scalar("actions/right",
action_probs[RailEnvActions.MOVE_RIGHT], episode_idx)
writer.add_scalar("actions/stop",
action_probs[RailEnvActions.STOP_MOVING],
episode_idx)
writer.add_scalar("training/epsilon", eps_start, episode_idx)
writer.add_scalar("training/buffer_size", len(policy.memory),
episode_idx)
writer.add_scalar("training/loss", policy.loss, episode_idx)
writer.add_scalar("timer/reset", reset_timer.get(), episode_idx)
writer.add_scalar("timer/step", step_timer.get(), episode_idx)
writer.add_scalar("timer/learn", learn_timer.get(), episode_idx)
writer.add_scalar("timer/preproc", preproc_timer.get(), episode_idx)
writer.add_scalar("timer/total", training_timer.get_current(),
episode_idx)
def eval_policy(env_params, checkpoint, n_eval_episodes, max_steps,
action_size, state_size, seed, render, allow_skipping,
allow_caching):
# Evaluation is faster on CPU (except if you use a really huge policy)
parameters = {'use_gpu': False}
policy = DDDQNPolicy(state_size,
action_size,
Namespace(**parameters),
evaluation_mode=True)
policy.qnetwork_local = torch.load(checkpoint)
env_params = Namespace(**env_params)
# Environment parameters
n_agents = env_params.n_agents
x_dim = env_params.x_dim
y_dim = env_params.y_dim
n_cities = env_params.n_cities
max_rails_between_cities = env_params.max_rails_between_cities
max_rails_in_city = env_params.max_rails_in_city
# Malfunction and speed profiles
# TODO pass these parameters properly from main!
malfunction_parameters = MalfunctionParameters(
malfunction_rate=1. / 2000, # Rate of malfunctions
min_duration=20, # Minimal duration
max_duration=50 # Max duration
)
# Only fast trains in Round 1
speed_profiles = {
1.: 1.0, # Fast passenger train
1. / 2.: 0.0, # Fast freight train
1. / 3.: 0.0, # Slow commuter train
1. / 4.: 0.0 # Slow freight train
}
# Observation parameters
observation_tree_depth = env_params.observation_tree_depth
observation_radius = env_params.observation_radius
observation_max_path_depth = env_params.observation_max_path_depth
# Observation builder
predictor = ShortestPathPredictorForRailEnv(observation_max_path_depth)
tree_observation = TreeObsForRailEnv(max_depth=observation_tree_depth,
predictor=predictor)
# Setup the environment
env = RailEnv(
width=x_dim,
height=y_dim,
rail_generator=sparse_rail_generator(
max_num_cities=n_cities,
grid_mode=False,
max_rails_between_cities=max_rails_between_cities,
max_rails_in_city=max_rails_in_city,
),
schedule_generator=sparse_schedule_generator(speed_profiles),
number_of_agents=n_agents,
malfunction_generator_and_process_data=malfunction_from_params(
malfunction_parameters),
obs_builder_object=tree_observation)
if render:
env_renderer = RenderTool(env, gl="PGL")
action_dict = dict()
scores = []
completions = []
nb_steps = []
inference_times = []
preproc_times = []
agent_times = []
step_times = []
for episode_idx in range(n_eval_episodes):
seed += 1
inference_timer = Timer()
preproc_timer = Timer()
agent_timer = Timer()
step_timer = Timer()
step_timer.start()
obs, info = env.reset(regenerate_rail=True,
regenerate_schedule=True,
random_seed=seed)
step_timer.end()
agent_obs = [None] * env.get_num_agents()
score = 0.0
if render:
env_renderer.set_new_rail()
final_step = 0
skipped = 0
nb_hit = 0
agent_last_obs = {}
agent_last_action = {}
for step in range(max_steps - 1):
if allow_skipping and check_if_all_blocked(env):
# FIXME why -1? bug where all agents are "done" after max_steps!
skipped = max_steps - step - 1
final_step = max_steps - 2
n_unfinished_agents = sum(not done[idx]
for idx in env.get_agent_handles())
score -= skipped * n_unfinished_agents
break
agent_timer.start()
for agent in env.get_agent_handles():
if obs[agent] and info['action_required'][agent]:
if agent in agent_last_obs and np.all(
agent_last_obs[agent] == obs[agent]):
nb_hit += 1
action = agent_last_action[agent]
else:
preproc_timer.start()
norm_obs = normalize_observation(
obs[agent],
tree_depth=observation_tree_depth,
observation_radius=observation_radius)
preproc_timer.end()
inference_timer.start()
action = policy.act(norm_obs, eps=0.0)
inference_timer.end()
action_dict.update({agent: action})
if allow_caching:
agent_last_obs[agent] = obs[agent]
agent_last_action[agent] = action
agent_timer.end()
step_timer.start()
obs, all_rewards, done, info = env.step(action_dict)
step_timer.end()
if render:
env_renderer.render_env(show=True,
frames=False,
show_observations=False,
show_predictions=False)
if step % 100 == 0:
print("{}/{}".format(step, max_steps - 1))
for agent in env.get_agent_handles():
score += all_rewards[agent]
final_step = step
if done['__all__']:
break
normalized_score = score / (max_steps * env.get_num_agents())
scores.append(normalized_score)
tasks_finished = sum(done[idx] for idx in env.get_agent_handles())
completion = tasks_finished / max(1, env.get_num_agents())
completions.append(completion)
nb_steps.append(final_step)
inference_times.append(inference_timer.get())
preproc_times.append(preproc_timer.get())
agent_times.append(agent_timer.get())
step_times.append(step_timer.get())
skipped_text = ""
if skipped > 0:
skipped_text = "\t⚡ Skipped {}".format(skipped)
hit_text = ""
if nb_hit > 0:
hit_text = "\t⚡ Hit {} ({:.1f}%)".format(nb_hit, (100 * nb_hit) /
(n_agents * final_step))
print(
"☑️ Score: {:.3f} \tDone: {:.1f}% \tNb steps: {:.3f} "
"\t🍭 Seed: {}"
"\t🚉 Env: {:.3f}s "
"\t🤖 Agent: {:.3f}s (per step: {:.3f}s) \t[preproc: {:.3f}s \tinfer: {:.3f}s]"
"{}{}".format(normalized_score, completion * 100.0, final_step,
seed, step_timer.get(), agent_timer.get(),
agent_timer.get() / final_step, preproc_timer.get(),
inference_timer.get(), skipped_text, hit_text))
return scores, completions, nb_steps, agent_times, step_times
def train_agent(n_episodes):
# Environment parameters
n_agents = 1
x_dim = 25
y_dim = 25
n_cities = 4
max_rails_between_cities = 2
max_rails_in_city = 3
seed = 42
# Observation parameters
observation_tree_depth = 2
observation_radius = 10
# Exploration parameters
eps_start = 1.0
eps_end = 0.01
eps_decay = 0.997 # for 2500ts
# Set the seeds
random.seed(seed)
np.random.seed(seed)
# Observation builder
tree_observation = TreeObsForRailEnv(max_depth=observation_tree_depth)
# Setup the environment
env = RailEnv(width=x_dim,
height=y_dim,
rail_generator=sparse_rail_generator(
max_num_cities=n_cities,
seed=seed,
grid_mode=False,
max_rails_between_cities=max_rails_between_cities,
max_rails_in_city=max_rails_in_city),
schedule_generator=sparse_schedule_generator(),
number_of_agents=n_agents,
obs_builder_object=tree_observation)
env.reset(True, True)
# Calculate the state size given the depth of the tree observation and the number of features
n_features_per_node = env.obs_builder.observation_dim
n_nodes = 0
for i in range(observation_tree_depth + 1):
n_nodes += np.power(4, i)
state_size = n_features_per_node * n_nodes
# The action space of flatland is 5 discrete actions
action_size = 5
# Max number of steps per episode
# This is the official formula used during evaluations
max_steps = int(4 * 2 * (env.height + env.width + (n_agents / n_cities)))
action_dict = dict()
# And some variables to keep track of the progress
scores_window = deque(maxlen=100) # todo smooth when rendering instead
completion_window = deque(maxlen=100)
scores = []
completion = []
action_count = [0] * action_size
agent_obs = [None] * env.get_num_agents()
agent_prev_obs = [None] * env.get_num_agents()
agent_prev_action = [2] * env.get_num_agents()
update_values = False
# Training parameters
training_parameters = {
'buffer_size': int(1e5),
'batch_size': 32,
'update_every': 8,
'learning_rate': 0.5e-4,
'tau': 1e-3,
'gamma': 0.99,
'buffer_min_size': 0,
'hidden_size': 256,
'use_gpu': False
}
# Double Dueling DQN policy
policy = DDDQNPolicy(state_size, action_size,
Namespace(**training_parameters))
for episode_idx in range(n_episodes):
score = 0
# Reset environment
obs, info = env.reset(regenerate_rail=True, regenerate_schedule=True)
# Build agent specific observations
for agent in env.get_agent_handles():
if obs[agent]:
agent_obs[agent] = normalize_observation(
obs[agent],
observation_tree_depth,
observation_radius=observation_radius)
agent_prev_obs[agent] = agent_obs[agent].copy()
# Run episode
for step in range(max_steps - 1):
for agent in env.get_agent_handles():
if info['action_required'][agent]:
# If an action is required, we want to store the obs at that step as well as the action
update_values = True
action = policy.act(agent_obs[agent], eps=eps_start)
action_count[action] += 1
else:
update_values = False
action = 0
action_dict.update({agent: action})
# Environment step
next_obs, all_rewards, done, info = env.step(action_dict)
# Update replay buffer and train agent
for agent in range(env.get_num_agents()):
# Only update the values when we are done or when an action was taken and thus relevant information is present
if update_values or done[agent]:
policy.step(agent_prev_obs[agent],
agent_prev_action[agent], all_rewards[agent],
agent_obs[agent], done[agent])
agent_prev_obs[agent] = agent_obs[agent].copy()
agent_prev_action[agent] = action_dict[agent]
if next_obs[agent]:
agent_obs[agent] = normalize_observation(
next_obs[agent],
observation_tree_depth,
observation_radius=10)
score += all_rewards[agent]
if done['__all__']:
break
# Epsilon decay
eps_start = max(eps_end, eps_decay * eps_start)
# Collection information about training
tasks_finished = np.sum(
[int(done[idx]) for idx in env.get_agent_handles()])
completion_window.append(tasks_finished / max(1, env.get_num_agents()))
scores_window.append(score / (max_steps * env.get_num_agents()))
completion.append((np.mean(completion_window)))
scores.append(np.mean(scores_window))
action_probs = action_count / np.sum(action_count)
if episode_idx % 100 == 0:
end = "\n"
torch.save(policy.qnetwork_local,
'./checkpoints/single-' + str(episode_idx) + '.pth')
action_count = [1] * action_size
else:
end = " "
print(
'\rTraining {} agents on {}x{}\t Episode {}\t Average Score: {:.3f}\tDones: {:.2f}%\tEpsilon: {:.2f} \t Action Probabilities: \t {}'
.format(env.get_num_agents(), x_dim, y_dim, episode_idx,
np.mean(scores_window), 100 * np.mean(completion_window),
eps_start, action_probs),
end=end)
# Plot overall training progress at the end
plt.plot(scores)
plt.show()
plt.plot(completion)
plt.show()