This commit is contained in:
allenzren
2024-09-03 21:03:27 -04:00
commit 8293b0936b
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"""
Parent fine-tuning agent class.
"""
import os
import numpy as np
from omegaconf import OmegaConf
import torch
import hydra
import logging
import wandb
import random
log = logging.getLogger(__name__)
from env.gym_utils import make_async
class TrainAgent:
def __init__(self, cfg):
super().__init__()
self.cfg = cfg
self.device = cfg.device
self.seed = cfg.get("seed", 42)
random.seed(self.seed)
np.random.seed(self.seed)
torch.manual_seed(self.seed)
# Wandb
self.use_wandb = cfg.wandb is not None
if cfg.wandb is not None:
wandb.init(
entity=cfg.wandb.entity,
project=cfg.wandb.project,
name=cfg.wandb.run,
config=OmegaConf.to_container(cfg, resolve=True),
)
# Make vectorized env
self.env_name = cfg.env.name
env_type = cfg.env.get("env_type", None)
self.venv = make_async(
cfg.env.name,
env_type=env_type,
num_envs=cfg.env.n_envs,
asynchronous=True,
max_episode_steps=cfg.env.max_episode_steps,
wrappers=cfg.env.get("wrappers", None),
robomimic_env_cfg_path=cfg.get("robomimic_env_cfg_path", None),
shape_meta=cfg.get("shape_meta", None),
use_image_obs=cfg.env.get("use_image_obs", False),
render=cfg.env.get("render", False),
render_offscreen=cfg.env.get("save_video", False),
obs_dim=cfg.obs_dim,
action_dim=cfg.action_dim,
**cfg.env.specific if "specific" in cfg.env else {},
)
if not env_type == "furniture":
self.venv.seed(
[self.seed + i for i in range(cfg.env.n_envs)]
) # otherwise parallel envs might have the same initial states!
# isaacgym environments do not need seeding
self.n_envs = cfg.env.n_envs
self.n_cond_step = cfg.cond_steps
self.obs_dim = cfg.obs_dim
self.action_dim = cfg.action_dim
self.act_steps = cfg.act_steps
self.horizon_steps = cfg.horizon_steps
self.max_episode_steps = cfg.env.max_episode_steps
self.reset_at_iteration = cfg.env.get("reset_at_iteration", True)
self.save_full_observations = cfg.env.get("save_full_observations", False)
self.furniture_sparse_reward = (
cfg.env.specific.get("sparse_reward", False)
if "specific" in cfg.env
else False
) # furniture specific, for best reward calculation
# Batch size for gradient update
self.batch_size: int = cfg.train.batch_size
# Build model and load checkpoint
self.model = hydra.utils.instantiate(cfg.model)
# Training params
self.itr = 0
self.n_train_itr = cfg.train.n_train_itr
self.val_freq = cfg.train.val_freq
self.force_train = cfg.train.get("force_train", False)
self.n_steps = cfg.train.n_steps
self.best_reward_threshold_for_success = (
len(self.venv.pairs_to_assemble)
if env_type == "furniture"
else cfg.env.best_reward_threshold_for_success
)
self.max_grad_norm = cfg.train.get("max_grad_norm", None)
# Logging, rendering, checkpoints
self.logdir = cfg.logdir
self.render_dir = os.path.join(self.logdir, "render")
self.checkpoint_dir = os.path.join(self.logdir, "checkpoint")
self.result_path = os.path.join(self.logdir, "result.pkl")
os.makedirs(self.render_dir, exist_ok=True)
os.makedirs(self.checkpoint_dir, exist_ok=True)
self.save_trajs = cfg.train.get("save_trajs", False)
self.log_freq = cfg.train.get("log_freq", 1)
self.save_model_freq = cfg.train.save_model_freq
self.render_freq = cfg.train.render.freq
self.n_render = cfg.train.render.num
self.render_video = cfg.env.get("save_video", False)
assert self.n_render <= self.n_envs, "n_render must be <= n_envs"
assert not (
self.n_render <= 0 and self.render_video
), "Need to set n_render > 0 if saving video"
self.traj_plotter = (
hydra.utils.instantiate(cfg.train.plotter)
if "plotter" in cfg.train
else None
)
def run(self):
pass
def save_model(self):
"""
saves model to disk; no ema
"""
data = {
"itr": self.itr,
"model": self.model.state_dict(),
}
savepath = os.path.join(self.checkpoint_dir, f"state_{self.itr}.pt")
torch.save(data, savepath)
log.info(f"Saved model to {savepath}")
def load(self, itr):
"""
loads model from disk
"""
loadpath = os.path.join(self.checkpoint_dir, f"state_{itr}.pt")
data = torch.load(loadpath, weights_only=True)
self.itr = data["itr"]
self.model.load_state_dict(data["model"])
def reset_env_all(self, verbose=False, options_venv=None, **kwargs):
if options_venv is None:
options_venv = [
{k: v for k, v in kwargs.items()} for _ in range(self.n_envs)
]
obs_venv = self.venv.reset_arg(options_list=options_venv)
# convert to OrderedDict if obs_venv is a list of dict
if isinstance(obs_venv, list):
obs_venv = {
key: np.stack([obs_venv[i][key] for i in range(self.n_envs)])
for key in obs_venv[0].keys()
}
if verbose:
for index in range(self.n_envs):
logging.info(
f"<-- Reset environment {index} with options {options_venv[index]}"
)
return obs_venv
def reset_env(self, env_ind, verbose=False):
task = {}
obs = self.venv.reset_one_arg(env_ind=env_ind, options=task)
if verbose:
logging.info(f"<-- Reset environment {env_ind} with task {task}")
return obs
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"""
Advantage-weighted regression (AWR) for diffusion policy.
Advantage = discounted-reward-to-go - V(s)
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
from copy import deepcopy
log = logging.getLogger(__name__)
from util.timer import Timer
from collections import deque
from agent.finetune.train_agent import TrainAgent
from util.scheduler import CosineAnnealingWarmupRestarts
def td_values(
states,
rewards,
dones,
state_values,
gamma=0.99,
alpha=0.95,
lam=0.95,
):
"""
Gives a list of TD estimates for a given list of samples from an RL environment.
The TD(λ) estimator is used for this computation.
:param replay_buffers: The replay buffers filled by exploring the RL environment.
Includes: states, rewards, "final state?"s.
:param state_values: The currently estimated state values.
:return: The TD estimates.
"""
sample_count = len(states)
tds = np.zeros_like(state_values, dtype=np.float32)
dones[-1] = 1
next_value = 1 - dones[-1]
val = 0.0
for i in range(sample_count - 1, -1, -1):
# next_value = 0.0 if dones[i] else state_values[i + 1]
# get next_value for vectorized
if i < sample_count - 1:
next_value = state_values[i + 1]
next_value = next_value * (1 - dones[i])
state_value = state_values[i]
error = rewards[i] + gamma * next_value - state_value
val = alpha * error + gamma * lam * (1 - dones[i]) * val
tds[i] = val + state_value
return tds
class TrainAWRDiffusionAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
self.logprob_batch_size = cfg.train.get("logprob_batch_size", 10000)
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Wwarm up period for critic before actor updates
self.n_critic_warmup_itr = cfg.train.n_critic_warmup_itr
# Optimizer
self.actor_optimizer = torch.optim.AdamW(
self.model.actor.parameters(),
lr=cfg.train.actor_lr,
weight_decay=cfg.train.actor_weight_decay,
)
self.actor_lr_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.actor_lr,
min_lr=cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_optimizer = torch.optim.AdamW(
self.model.critic.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
# Buffer size
self.buffer_size = cfg.train.buffer_size
# Reward exponential
self.beta = cfg.train.beta
# Max weight for AWR
self.max_adv_weight = cfg.train.max_adv_weight
# Scaling reward
self.scale_reward_factor = cfg.train.scale_reward_factor
# Updates
self.replay_ratio = cfg.train.replay_ratio
self.critic_update_ratio = cfg.train.critic_update_ratio
def run(self):
# make a FIFO replay buffer for obs, action, and reward
obs_buffer = deque(maxlen=self.buffer_size)
action_buffer = deque(maxlen=self.buffer_size)
reward_buffer = deque(maxlen=self.buffer_size)
done_buffer = deque(maxlen=self.buffer_size)
first_buffer = deque(maxlen=self.buffer_size)
# Start training loop
timer = Timer()
run_results = []
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
# Reset env at the beginning of an iteration
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
last_itr_eval = eval_mode
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = (
self.model(
cond=torch.from_numpy(prev_obs_venv)
.float()
.to(self.device),
deterministic=eval_mode,
)
.cpu()
.numpy()
) # n_env x horizon x act
action_venv = samples[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
# add to buffer
obs_buffer.append(prev_obs_venv)
action_buffer.append(action_venv)
reward_buffer.append(reward_venv * self.scale_reward_factor)
done_buffer.append(done_venv)
first_buffer.append(firsts_trajs[step])
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
obs_trajs = np.array(deepcopy(obs_buffer))
reward_trajs = np.array(deepcopy(reward_buffer))
dones_trajs = np.array(deepcopy(done_buffer))
obs_t = einops.rearrange(
torch.from_numpy(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
values_t = np.array(self.model.critic(obs_t).detach().cpu().numpy())
values_trajs = values_t.reshape(-1, self.n_envs)
td_trajs = td_values(obs_trajs, reward_trajs, dones_trajs, values_trajs)
# flatten
obs_trajs = einops.rearrange(
obs_trajs,
"s e h d -> (s e) h d",
)
td_trajs = einops.rearrange(
td_trajs,
"s e -> (s e)",
)
# Update policy and critic
num_batch = int(
self.n_steps * self.n_envs / self.batch_size * self.replay_ratio
)
for _ in range(num_batch // self.critic_update_ratio):
# Sample batch
inds = np.random.choice(len(obs_trajs), self.batch_size)
obs_b = torch.from_numpy(obs_trajs[inds]).float().to(self.device)
td_b = torch.from_numpy(td_trajs[inds]).float().to(self.device)
# Update critic
loss_critic = self.model.loss_critic(obs_b, td_b)
self.critic_optimizer.zero_grad()
loss_critic.backward()
self.critic_optimizer.step()
obs_trajs = np.array(deepcopy(obs_buffer))
samples_trajs = np.array(deepcopy(action_buffer))
reward_trajs = np.array(deepcopy(reward_buffer))
dones_trajs = np.array(deepcopy(done_buffer))
obs_t = einops.rearrange(
torch.from_numpy(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
values_t = np.array(self.model.critic(obs_t).detach().cpu().numpy())
values_trajs = values_t.reshape(-1, self.n_envs)
td_trajs = td_values(obs_trajs, reward_trajs, dones_trajs, values_trajs)
advantages_trajs = td_trajs - values_trajs
# flatten
obs_trajs = einops.rearrange(
obs_trajs,
"s e h d -> (s e) h d",
)
samples_trajs = einops.rearrange(
samples_trajs,
"s e h d -> (s e) h d",
)
advantages_trajs = einops.rearrange(
advantages_trajs,
"s e -> (s e)",
)
for _ in range(num_batch):
# Sample batch
inds = np.random.choice(len(obs_trajs), self.batch_size)
obs_b = torch.from_numpy(obs_trajs[inds]).float().to(self.device)
actions_b = (
torch.from_numpy(samples_trajs[inds]).float().to(self.device)
)
advantages_b = (
torch.from_numpy(advantages_trajs[inds]).float().to(self.device)
)
advantages_b = (advantages_b - advantages_b.mean()) / (
advantages_b.std() + 1e-6
)
advantages_b_scaled = torch.exp(self.beta * advantages_b)
advantages_b_scaled.clamp_(max=self.max_adv_weight)
# Update policy with collected trajectories
loss = self.model.loss(
actions_b,
obs_b,
advantages_b_scaled.detach(),
)
self.actor_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
# Update lr
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | reward {avg_episode_reward:8.4f} |t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"loss - critic": loss_critic,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["loss_critic"] = loss_critic
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
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"""
Model-free online RL with DIffusion POlicy (DIPO)
Applies action gradient to perturb actions towards maximizer of Q-function.
a_t <- a_t + \eta * \grad_a Q(s, a)
"""
import os
import pickle
import numpy as np
import torch
import logging
import wandb
log = logging.getLogger(__name__)
from util.timer import Timer
from collections import deque
from agent.finetune.train_agent import TrainAgent
from util.scheduler import CosineAnnealingWarmupRestarts
class TrainDIPODiffusionAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Wwarm up period for critic before actor updates
self.n_critic_warmup_itr = cfg.train.n_critic_warmup_itr
# Optimizer
self.actor_optimizer = torch.optim.AdamW(
self.model.actor.parameters(),
lr=cfg.train.actor_lr,
weight_decay=cfg.train.actor_weight_decay,
)
# use cosine scheduler with linear warmup
self.actor_lr_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.actor_lr,
min_lr=cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_optimizer = torch.optim.AdamW(
self.model.critic.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
# Buffer size
self.buffer_size = cfg.train.buffer_size
# Perturbation scale
self.eta = cfg.train.eta
# Updates
self.replay_ratio = cfg.train.replay_ratio
# Scaling reward
self.scale_reward_factor = cfg.train.scale_reward_factor
# Apply action gradient many steps
self.action_gradient_steps = cfg.train.action_gradient_steps
def run(self):
# make a FIFO replay buffer for obs, action, and reward
obs_buffer = deque(maxlen=self.buffer_size)
next_obs_buffer = deque(maxlen=self.buffer_size)
action_buffer = deque(maxlen=self.buffer_size)
reward_buffer = deque(maxlen=self.buffer_size)
done_buffer = deque(maxlen=self.buffer_size)
first_buffer = deque(maxlen=self.buffer_size)
# Start training loop
timer = Timer()
run_results = []
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
# Reset env at the beginning of an iteration
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
last_itr_eval = eval_mode
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = (
self.model(
cond=torch.from_numpy(prev_obs_venv)
.float()
.to(self.device),
deterministic=eval_mode,
)
.cpu()
.numpy()
) # n_env x horizon x act
action_venv = samples[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
# add to buffer
for i in range(self.n_envs):
obs_buffer.append(prev_obs_venv[i])
next_obs_buffer.append(obs_venv[i])
action_buffer.append(action_venv[i])
reward_buffer.append(reward_venv[i] * self.scale_reward_factor)
done_buffer.append(done_venv[i])
first_buffer.append(firsts_trajs[step])
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
if not eval_mode:
num_batch = self.replay_ratio
# Critic learning
for _ in range(num_batch):
# Sample batch
inds = np.random.choice(len(obs_buffer), self.batch_size)
obs_b = (
torch.from_numpy(np.vstack([obs_buffer[i][None] for i in inds]))
.float()
.to(self.device)
)
next_obs_b = (
torch.from_numpy(
np.vstack([next_obs_buffer[i][None] for i in inds])
)
.float()
.to(self.device)
)
actions_b = (
torch.from_numpy(
np.vstack([action_buffer[i][None] for i in inds])
)
.float()
.to(self.device)
)
rewards_b = (
torch.from_numpy(np.vstack([reward_buffer[i] for i in inds]))
.float()
.to(self.device)
)
dones_b = (
torch.from_numpy(np.vstack([done_buffer[i] for i in inds]))
.float()
.to(self.device)
)
# Update critic
loss_critic = self.model.loss_critic(
obs_b, next_obs_b, actions_b, rewards_b, dones_b, self.gamma
)
self.critic_optimizer.zero_grad()
loss_critic.backward()
self.critic_optimizer.step()
# Actor learning
for _ in range(num_batch):
# Sample batch
inds = np.random.choice(len(obs_buffer), self.batch_size)
obs_b = (
torch.from_numpy(np.vstack([obs_buffer[i][None] for i in inds]))
.float()
.to(self.device)
)
actions_b = (
torch.from_numpy(
np.vstack([action_buffer[i][None] for i in inds])
)
.float()
.to(self.device)
)
# Replace actions in buffer with guided actions
guided_action_list = []
# get Q-perturbed actions by optimizing
actions_flat = actions_b.reshape(actions_b.shape[0], -1)
actions_optim = torch.optim.Adam(
[actions_flat], lr=self.eta, eps=1e-5
)
for _ in range(self.action_gradient_steps):
actions_flat.requires_grad_(True)
q_values_1, q_values_2 = self.model.critic(obs_b, actions_flat)
q_values = torch.min(q_values_1, q_values_2)
action_opt_loss = -q_values.sum()
actions_optim.zero_grad()
action_opt_loss.backward(torch.ones_like(action_opt_loss))
# get the perturbed action
actions_optim.step()
actions_flat.requires_grad_(False)
actions_flat.clamp_(-1.0, 1.0)
guided_action = actions_flat.detach()
guided_action = guided_action.reshape(
guided_action.shape[0], -1, self.action_dim
)
guided_action_list.append(guided_action)
guided_action_stacked = torch.cat(guided_action_list, 0)
# Add to buffer (need separate indices since we're working with a limited subset)
for i, i_buf in enumerate(inds):
action_buffer[i_buf] = (
guided_action_stacked[i].detach().cpu().numpy()
)
# Update policy with collected trajectories
loss = self.model.loss(guided_action.detach(), {0: obs_b})
self.actor_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
# Update lr
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | reward {avg_episode_reward:8.4f} |t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"loss - critic": loss_critic,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["loss_critic"] = loss_critic
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
+317
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@@ -0,0 +1,317 @@
"""
Diffusion Q-Learning (DQL)
Learns a critic Q-function and backprops the expected Q-value to train the actor
pi = argmin L_d(\theta) - \alpha * E[Q(s, a)]
L_d is demonstration loss for regularization
"""
import os
import pickle
import numpy as np
import torch
import logging
import wandb
log = logging.getLogger(__name__)
from util.timer import Timer
from collections import deque
from agent.finetune.train_agent import TrainAgent
from util.scheduler import CosineAnnealingWarmupRestarts
class TrainDQLDiffusionAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Wwarm up period for critic before actor updates
self.n_critic_warmup_itr = cfg.train.n_critic_warmup_itr
# Optimizer
self.actor_optimizer = torch.optim.AdamW(
self.model.actor.parameters(),
lr=cfg.train.actor_lr,
weight_decay=cfg.train.actor_weight_decay,
)
# use cosine scheduler with linear warmup
self.actor_lr_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.actor_lr,
min_lr=cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_optimizer = torch.optim.AdamW(
self.model.critic.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
# Buffer size
self.buffer_size = cfg.train.buffer_size
# Perturbation scale
self.eta = cfg.train.eta
# Reward factor - scale down mujoco reward for better critic training
self.scale_reward_factor = cfg.train.scale_reward_factor
# Updates
self.replay_ratio = cfg.train.replay_ratio
def run(self):
# make a FIFO replay buffer for obs, action, and reward
obs_buffer = deque(maxlen=self.buffer_size)
next_obs_buffer = deque(maxlen=self.buffer_size)
action_buffer = deque(maxlen=self.buffer_size)
reward_buffer = deque(maxlen=self.buffer_size)
done_buffer = deque(maxlen=self.buffer_size)
first_buffer = deque(maxlen=self.buffer_size)
# Start training loop
timer = Timer()
run_results = []
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
# Reset env at the beginning of an iteration
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
last_itr_eval = eval_mode
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = (
self.model(
cond=torch.from_numpy(prev_obs_venv)
.float()
.to(self.device),
deterministic=eval_mode,
)
.cpu()
.numpy()
) # n_env x horizon x act
action_venv = samples[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
# add to buffer
for i in range(self.n_envs):
obs_buffer.append(prev_obs_venv[i])
next_obs_buffer.append(obs_venv[i])
action_buffer.append(action_venv[i])
reward_buffer.append(reward_venv[i] * self.scale_reward_factor)
done_buffer.append(done_venv[i])
first_buffer.append(firsts_trajs[step])
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
if not eval_mode:
num_batch = self.replay_ratio
# Critic learning
for _ in range(num_batch):
# Sample batch
inds = np.random.choice(len(obs_buffer), self.batch_size)
obs_b = (
torch.from_numpy(np.vstack([obs_buffer[i][None] for i in inds]))
.float()
.to(self.device)
)
next_obs_b = (
torch.from_numpy(
np.vstack([next_obs_buffer[i][None] for i in inds])
)
.float()
.to(self.device)
)
actions_b = (
torch.from_numpy(
np.vstack([action_buffer[i][None] for i in inds])
)
.float()
.to(self.device)
)
rewards_b = (
torch.from_numpy(np.vstack([reward_buffer[i] for i in inds]))
.float()
.to(self.device)
)
dones_b = (
torch.from_numpy(np.vstack([done_buffer[i] for i in inds]))
.float()
.to(self.device)
)
# Update critic
loss_critic = self.model.loss_critic(
obs_b, next_obs_b, actions_b, rewards_b, dones_b, self.gamma
)
self.critic_optimizer.zero_grad()
loss_critic.backward()
self.critic_optimizer.step()
# get the new action and q values
samples = self.model.forward_train(
cond=obs_b.to(self.device),
deterministic=eval_mode,
)
output_venv = samples # n_env x horizon x act
action_venv = output_venv[:, : self.act_steps, : self.action_dim]
actions_flat_b = action_venv.reshape(action_venv.shape[0], -1)
q_values_b = self.model.critic(obs_b, actions_flat_b)
q1_new_action, q2_new_action = q_values_b
# Update policy with collected trajectories
self.actor_optimizer.zero_grad()
actor_loss = self.model.loss_actor(
obs_b, actions_b, q1_new_action, q2_new_action, self.eta
)
actor_loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
loss = actor_loss
# Update lr
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | reward {avg_episode_reward:8.4f} |t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"loss - critic": loss_critic,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["loss_critic"] = loss_critic
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
@@ -0,0 +1,347 @@
"""
Implicit diffusion Q-learning (IDQL) trainer for diffusion policy.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
from copy import deepcopy
import random
log = logging.getLogger(__name__)
from util.timer import Timer
from collections import deque
from agent.finetune.train_agent import TrainAgent
from util.scheduler import CosineAnnealingWarmupRestarts
class TrainIDQLDiffusionAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Wwarm up period for critic before actor updates
self.n_critic_warmup_itr = cfg.train.n_critic_warmup_itr
# Optimizer
self.actor_optimizer = torch.optim.AdamW(
self.model.actor.parameters(),
lr=cfg.train.actor_lr,
weight_decay=cfg.train.actor_weight_decay,
)
self.actor_lr_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.actor_lr,
min_lr=cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_q_optimizer = torch.optim.AdamW(
self.model.critic_q.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_v_optimizer = torch.optim.AdamW(
self.model.critic_v.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_v_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_v_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_q_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_q_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
# Buffer size
self.buffer_size = cfg.train.buffer_size
# Actor params
self.use_expectile_exploration = cfg.train.use_expectile_exploration
# Scaling reward
self.scale_reward_factor = cfg.train.scale_reward_factor
# Updates
self.replay_ratio = cfg.train.replay_ratio
self.critic_tau = cfg.train.critic_tau
# Whether to use deterministic mode when sampling at eval
self.eval_deterministic = cfg.train.get("eval_deterministic", False)
# Sampling
self.num_sample = cfg.train.eval_sample_num
def run(self):
# make a FIFO replay buffer for obs, action, and reward
obs_buffer = deque(maxlen=self.buffer_size)
action_buffer = deque(maxlen=self.buffer_size)
next_obs_buffer = deque(maxlen=self.buffer_size)
reward_buffer = deque(maxlen=self.buffer_size)
done_buffer = deque(maxlen=self.buffer_size)
first_buffer = deque(maxlen=self.buffer_size)
# Start training loop
timer = Timer()
run_results = []
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
# Reset env at the beginning of an iteration
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
last_itr_eval = eval_mode
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = (
self.model(
cond=torch.from_numpy(prev_obs_venv)
.float()
.to(self.device),
deterministic=eval_mode and self.eval_deterministic,
num_sample=self.num_sample,
use_expectile_exploration=self.use_expectile_exploration,
)
.cpu()
.numpy()
) # n_env x horizon x act
action_venv = samples[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
# add to buffer
obs_buffer.append(prev_obs_venv)
action_buffer.append(action_venv)
next_obs_buffer.append(obs_venv)
reward_buffer.append(reward_venv * self.scale_reward_factor)
done_buffer.append(done_venv)
first_buffer.append(firsts_trajs[step])
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
obs_trajs = np.array(deepcopy(obs_buffer))
action_trajs = np.array(deepcopy(action_buffer))
next_obs_trajs = np.array(deepcopy(next_obs_buffer))
reward_trajs = np.array(deepcopy(reward_buffer))
done_trajs = np.array(deepcopy(done_buffer))
first_trajs = np.array(deepcopy(first_buffer))
# flatten
obs_trajs = einops.rearrange(
obs_trajs,
"s e h d -> (s e) h d",
)
next_obs_trajs = einops.rearrange(
next_obs_trajs,
"s e h d -> (s e) h d",
)
action_trajs = einops.rearrange(
action_trajs,
"s e h d -> (s e) h d",
)
reward_trajs = reward_trajs.reshape(-1)
done_trajs = done_trajs.reshape(-1)
first_trajs = first_trajs.reshape(-1)
num_batch = int(
self.n_steps * self.n_envs / self.batch_size * self.replay_ratio
)
for _ in range(num_batch):
# Sample batch
inds = np.random.choice(len(obs_trajs), self.batch_size)
obs_b = torch.from_numpy(obs_trajs[inds]).float().to(self.device)
next_obs_b = (
torch.from_numpy(next_obs_trajs[inds]).float().to(self.device)
)
actions_b = (
torch.from_numpy(action_trajs[inds]).float().to(self.device)
)
reward_b = (
torch.from_numpy(reward_trajs[inds]).float().to(self.device)
)
done_b = torch.from_numpy(done_trajs[inds]).float().to(self.device)
# update critic value function
critic_loss_v = self.model.loss_critic_v(obs_b, actions_b)
self.critic_v_optimizer.zero_grad()
critic_loss_v.backward()
self.critic_v_optimizer.step()
# update critic q function
critic_loss_q = self.model.loss_critic_q(
obs_b, next_obs_b, actions_b, reward_b, done_b, self.gamma
)
self.critic_q_optimizer.zero_grad()
critic_loss_q.backward()
self.critic_q_optimizer.step()
# update target q function
self.model.update_target_critic(self.critic_tau)
loss_critic = critic_loss_q.detach() + critic_loss_v.detach()
# Update policy with collected trajectories - no weighting
loss = self.model.loss(
actions_b,
obs_b,
)
self.actor_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
# Update lr
self.actor_lr_scheduler.step()
self.critic_v_lr_scheduler.step()
self.critic_q_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | reward {avg_episode_reward:8.4f} |t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"loss - critic": loss_critic,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["loss_critic"] = loss_critic
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
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"""
Parent PPO fine-tuning agent class.
"""
from typing import Optional
import torch
import logging
from util.scheduler import CosineAnnealingWarmupRestarts
log = logging.getLogger(__name__)
from agent.finetune.train_agent import TrainAgent
from util.reward_scaling import RunningRewardScaler
class TrainPPOAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
# Batch size for logprobs calculations after an iteration --- prevent out of memory if using a single batch
self.logprob_batch_size = cfg.train.get("logprob_batch_size", 10000)
assert (
self.logprob_batch_size % self.n_envs == 0
), "logprob_batch_size must be divisible by n_envs"
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Wwarm up period for critic before actor updates
self.n_critic_warmup_itr = cfg.train.n_critic_warmup_itr
# Optimizer
self.actor_optimizer = torch.optim.AdamW(
self.model.actor_ft.parameters(),
lr=cfg.train.actor_lr,
weight_decay=cfg.train.actor_weight_decay,
)
# use cosine scheduler with linear warmup
self.actor_lr_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.actor_lr,
min_lr=cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_optimizer = torch.optim.AdamW(
self.model.critic.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
# Generalized advantage estimation
self.gae_lambda: float = cfg.train.get("gae_lambda", 0.95)
# If specified, stop gradient update once KL difference reaches it
self.target_kl: Optional[float] = cfg.train.target_kl
# Number of times the collected data is used in gradient update
self.update_epochs: int = cfg.train.update_epochs
# Entropy loss coefficient
self.ent_coef: float = cfg.train.get("ent_coef", 0)
# Value loss coefficient
self.vf_coef: float = cfg.train.get("vf_coef", 0)
# Whether to use running reward scaling
self.reward_scale_running: bool = cfg.train.reward_scale_running
if self.reward_scale_running:
self.running_reward_scaler = RunningRewardScaler(self.n_envs)
# Scaling reward with constant
self.reward_scale_const: float = cfg.train.get("reward_scale_const", 1)
# Use base policy
self.use_bc_loss: bool = cfg.train.get("use_bc_loss", False)
self.bc_loss_coeff: float = cfg.train.get("bc_loss_coeff", 0)
def reset_actor_optimizer(self):
"""Not used anywhere currently"""
new_optimizer = torch.optim.AdamW(
self.model.actor_ft.parameters(),
lr=self.cfg.train.actor_lr,
weight_decay=self.cfg.train.actor_weight_decay,
)
new_optimizer.load_state_dict(self.actor_optimizer.state_dict())
self.actor_optimizer = new_optimizer
new_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=self.cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=self.cfg.train.actor_lr,
min_lr=self.cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=self.cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
new_scheduler.load_state_dict(self.actor_lr_scheduler.state_dict())
self.actor_lr_scheduler = new_scheduler
log.info("Reset actor optimizer")
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"""
DPPO fine-tuning.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
log = logging.getLogger(__name__)
from util.timer import Timer
from agent.finetune.train_ppo_agent import TrainPPOAgent
from util.scheduler import CosineAnnealingWarmupRestarts
class TrainPPODiffusionAgent(TrainPPOAgent):
def __init__(self, cfg):
super().__init__(cfg)
# Reward horizon --- always set to act_steps for now
self.reward_horizon = cfg.get("reward_horizon", self.act_steps)
# Eta - between DDIM (=0 for eval) and DDPM (=1 for training)
self.learn_eta = self.model.learn_eta
if self.learn_eta:
self.eta_update_interval = cfg.train.eta_update_interval
self.eta_optimizer = torch.optim.AdamW(
self.model.eta.parameters(),
lr=cfg.train.eta_lr,
weight_decay=cfg.train.eta_weight_decay,
)
self.eta_lr_scheduler = CosineAnnealingWarmupRestarts(
self.eta_optimizer,
first_cycle_steps=cfg.train.eta_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.eta_lr,
min_lr=cfg.train.eta_lr_scheduler.min_lr,
warmup_steps=cfg.train.eta_lr_scheduler.warmup_steps,
gamma=1.0,
)
def run(self):
# Start training loop
timer = Timer()
run_results = []
last_itr_eval = False
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
last_itr_eval = eval_mode
# Reset env before iteration starts (1) if specified, (2) at eval mode, or (3) right after eval mode
dones_trajs = np.empty((0, self.n_envs))
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
# Holder
obs_trajs = np.empty((0, self.n_envs, self.n_cond_step, self.obs_dim))
chains_trajs = np.empty(
(
0,
self.n_envs,
self.model.ft_denoising_steps + 1,
self.horizon_steps,
self.action_dim,
)
)
reward_trajs = np.empty((0, self.n_envs))
obs_full_trajs = np.empty((0, self.n_envs, self.obs_dim))
obs_full_trajs = np.vstack(
(obs_full_trajs, prev_obs_venv[None].squeeze(2))
) # remove cond_step dim
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = self.model(
cond=torch.from_numpy(prev_obs_venv).float().to(self.device),
deterministic=eval_mode,
return_chain=True,
)
output_venv = (
samples.trajectories.cpu().numpy()
) # n_env x horizon x act
chains_venv = (
samples.chains.cpu().numpy()
) # n_env x denoising x horizon x act
action_venv = output_venv[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
if self.save_full_observations:
obs_full_venv = np.vstack(
[info["full_obs"][None] for info in info_venv]
) # n_envs x n_act_steps x obs_dim
obs_full_trajs = np.vstack(
(obs_full_trajs, obs_full_venv.transpose(1, 0, 2))
)
obs_trajs = np.vstack((obs_trajs, prev_obs_venv[None]))
chains_trajs = np.vstack((chains_trajs, chains_venv[None]))
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
dones_trajs = np.vstack((dones_trajs, done_venv[None]))
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
if (
self.furniture_sparse_reward
): # only for furniture tasks, where reward only occurs in one env step
episode_best_reward = episode_reward
else:
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update models
if not eval_mode:
with torch.no_grad():
# Calculate value and logprobs - split into batches to prevent out of memory
obs_t = einops.rearrange(
torch.from_numpy(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
obs_ts = torch.split(obs_t, self.logprob_batch_size, dim=0)
values_trajs = np.empty((0, self.n_envs))
for obs in obs_ts:
values = self.model.critic(obs).cpu().numpy().flatten()
values_trajs = np.vstack(
(values_trajs, values.reshape(-1, self.n_envs))
)
chains_t = einops.rearrange(
torch.from_numpy(chains_trajs).float().to(self.device),
"s e t h d -> (s e) t h d",
)
chains_ts = torch.split(chains_t, self.logprob_batch_size, dim=0)
logprobs_trajs = np.empty(
(
0,
self.model.ft_denoising_steps,
self.horizon_steps,
self.action_dim,
)
)
for obs, chains in zip(obs_ts, chains_ts):
logprobs = self.model.get_logprobs(obs, chains).cpu().numpy()
logprobs_trajs = np.vstack(
(
logprobs_trajs,
logprobs.reshape(-1, *logprobs_trajs.shape[1:]),
)
)
# normalize reward with running variance if specified
if self.reward_scale_running:
reward_trajs_transpose = self.running_reward_scaler(
reward=reward_trajs.T, first=firsts_trajs[:-1].T
)
reward_trajs = reward_trajs_transpose.T
# bootstrap value with GAE if not done - apply reward scaling with constant if specified
obs_venv_ts = torch.from_numpy(obs_venv).float().to(self.device)
with torch.no_grad():
next_value = (
self.model.critic(obs_venv_ts).reshape(1, -1).cpu().numpy()
)
advantages_trajs = np.zeros_like(reward_trajs)
lastgaelam = 0
for t in reversed(range(self.n_steps)):
if t == self.n_steps - 1:
nextnonterminal = 1.0 - done_venv
nextvalues = next_value
else:
nextnonterminal = 1.0 - dones_trajs[t + 1]
nextvalues = values_trajs[t + 1]
# delta = r + gamma*V(st+1) - V(st)
delta = (
reward_trajs[t] * self.reward_scale_const
+ self.gamma * nextvalues * nextnonterminal
- values_trajs[t]
)
# A = delta_t + gamma*lamdba*delta_{t+1} + ...
advantages_trajs[t] = lastgaelam = (
delta
+ self.gamma
* self.gae_lambda
* nextnonterminal
* lastgaelam
)
returns_trajs = advantages_trajs + values_trajs
# k for environment step
obs_k = einops.rearrange(
torch.tensor(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
chains_k = einops.rearrange(
torch.tensor(chains_trajs).float().to(self.device),
"s e t h d -> (s e) t h d",
)
returns_k = (
torch.tensor(returns_trajs).float().to(self.device).reshape(-1)
)
values_k = (
torch.tensor(values_trajs).float().to(self.device).reshape(-1)
)
advantages_k = (
torch.tensor(advantages_trajs).float().to(self.device).reshape(-1)
)
logprobs_k = torch.tensor(logprobs_trajs).float().to(self.device)
# Update policy and critic
total_steps = self.n_steps * self.n_envs
inds_k = np.arange(total_steps)
clipfracs = []
for update_epoch in range(self.update_epochs):
# for each epoch, go through all data in batches
flag_break = False
np.random.shuffle(inds_k)
num_batch = max(1, total_steps // self.batch_size) # skip last ones
for batch in range(num_batch):
start = batch * self.batch_size
end = start + self.batch_size
inds_b = inds_k[start:end] # b for batch
obs_b = obs_k[inds_b]
chains_b = chains_k[inds_b]
returns_b = returns_k[inds_b]
values_b = values_k[inds_b]
advantages_b = advantages_k[inds_b]
logprobs_b = logprobs_k[inds_b]
# get loss
(
pg_loss,
entropy_loss,
v_loss,
clipfrac,
approx_kl,
ratio,
bc_loss,
eta,
) = self.model.loss(
obs_b,
chains_b,
returns_b,
values_b,
advantages_b,
logprobs_b,
use_bc_loss=self.use_bc_loss,
reward_horizon=self.reward_horizon,
)
loss = (
pg_loss
+ entropy_loss * self.ent_coef
+ v_loss * self.vf_coef
+ bc_loss * self.bc_loss_coeff
)
clipfracs += [clipfrac]
# update policy and critic
self.actor_optimizer.zero_grad()
self.critic_optimizer.zero_grad()
if self.learn_eta:
self.eta_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor_ft.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
if self.learn_eta and batch % self.eta_update_interval == 0:
self.eta_optimizer.step()
self.critic_optimizer.step()
log.info(
f"approx_kl: {approx_kl}, update_epoch: {update_epoch}, num_batch: {num_batch}"
)
# Stop gradient update if KL difference reaches target
if self.target_kl is not None and approx_kl > self.target_kl:
flag_break = True
break
if flag_break:
break
# Explained variation of future rewards using value function
y_pred, y_true = values_k.cpu().numpy(), returns_k.cpu().numpy()
var_y = np.var(y_true)
explained_var = (
np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
)
# Plot state trajectories in D3IL
if (
self.itr % self.render_freq == 0
and self.n_render > 0
and self.traj_plotter is not None
):
self.traj_plotter(
obs_full_trajs=obs_full_trajs,
n_render=self.n_render,
max_episode_steps=self.max_episode_steps,
render_dir=self.render_dir,
itr=self.itr,
)
# Update lr, min_sampling_std
if self.itr >= self.n_critic_warmup_itr:
self.actor_lr_scheduler.step()
if self.learn_eta:
self.eta_lr_scheduler.step()
self.critic_lr_scheduler.step()
self.model.step()
diffusion_min_sampling_std = self.model.get_min_sampling_denoising_std()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.save_trajs:
run_results[-1]["obs_full_trajs"] = obs_full_trajs
run_results[-1]["obs_trajs"] = obs_trajs
run_results[-1]["chains_trajs"] = chains_trajs
run_results[-1]["reward_trajs"] = reward_trajs
if self.itr % self.log_freq == 0:
time = timer()
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | pg loss {pg_loss:8.4f} | value loss {v_loss:8.4f} | bc loss {bc_loss:8.4f} | reward {avg_episode_reward:8.4f} | eta {eta:8.4f} | t:{time:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"pg loss": pg_loss,
"value loss": v_loss,
"bc loss": bc_loss,
"eta": eta,
"approx kl": approx_kl,
"ratio": ratio,
"clipfrac": np.mean(clipfracs),
"explained variance": explained_var,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
"diffusion - min sampling std": diffusion_min_sampling_std,
"actor lr": self.actor_optimizer.param_groups[0]["lr"],
"critic lr": self.critic_optimizer.param_groups[0][
"lr"
],
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["pg_loss"] = pg_loss
run_results[-1]["value_loss"] = v_loss
run_results[-1]["bc_loss"] = bc_loss
run_results[-1]["eta"] = eta
run_results[-1]["approx_kl"] = approx_kl
run_results[-1]["ratio"] = ratio
run_results[-1]["clip_frac"] = np.mean(clipfracs)
run_results[-1]["explained_variance"] = explained_var
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = time
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
@@ -0,0 +1,468 @@
"""
DPPO fine-tuning for pixel observations.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
import math
log = logging.getLogger(__name__)
from util.timer import Timer
from agent.finetune.train_ppo_diffusion_agent import TrainPPODiffusionAgent
from model.common.modules import RandomShiftsAug
class TrainPPOImgDiffusionAgent(TrainPPODiffusionAgent):
def __init__(self, cfg):
super().__init__(cfg)
# Image randomization
self.augment = cfg.train.augment
if self.augment:
self.aug = RandomShiftsAug(pad=4)
# Set obs dim - we will save the different obs in batch in a dict
shape_meta = cfg.shape_meta
self.obs_dims = {k: shape_meta.obs[k]["shape"] for k in shape_meta.obs.keys()}
# Gradient accumulation to deal with large GPU RAM usage
self.grad_accumulate = cfg.train.grad_accumulate
def run(self):
# Start training loop
timer = Timer()
run_results = []
last_itr_eval = False
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
last_itr_eval = eval_mode
# Reset env before iteration starts (1) if specified, (2) at eval mode, or (3) right after eval mode
dones_trajs = np.empty((0, self.n_envs))
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
# Holder
obs_trajs = {
k: np.empty((0, self.n_envs, self.n_cond_step, *self.obs_dims[k]))
for k in self.obs_dims
}
chains_trajs = np.empty(
(
0,
self.n_envs,
self.model.ft_denoising_steps + 1,
self.horizon_steps,
self.action_dim,
)
)
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
cond = {
key: torch.from_numpy(prev_obs_venv[key])
.float()
.to(self.device)
for key in self.obs_dims.keys()
} # batch each type of obs and put into dict
samples = self.model(
cond=cond,
deterministic=eval_mode,
return_chain=True,
)
output_venv = (
samples.trajectories.cpu().numpy()
) # n_env x horizon x act
chains_venv = (
samples.chains.cpu().numpy()
) # n_env x denoising x horizon x act
action_venv = output_venv[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
for k in obs_trajs.keys():
obs_trajs[k] = np.vstack((obs_trajs[k], prev_obs_venv[k][None]))
chains_trajs = np.vstack((chains_trajs, chains_venv[None]))
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
dones_trajs = np.vstack((dones_trajs, done_venv[None]))
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
with torch.no_grad():
# apply image randomization
obs_trajs["rgb"] = (
torch.from_numpy(obs_trajs["rgb"]).float().to(self.device)
)
obs_trajs["state"] = (
torch.from_numpy(obs_trajs["state"]).float().to(self.device)
)
if self.augment:
rgb = einops.rearrange(
obs_trajs["rgb"],
"s e t c h w -> (s e t) c h w",
)
rgb = self.aug(rgb)
obs_trajs["rgb"] = einops.rearrange(
rgb,
"(s e t) c h w -> s e t c h w",
s=self.n_steps,
e=self.n_envs,
)
# Calculate value and logprobs - split into batches to prevent out of memory
num_split = math.ceil(
self.n_envs * self.n_steps / self.logprob_batch_size
)
obs_ts = [{} for _ in range(num_split)]
for k in obs_trajs.keys():
obs_k = einops.rearrange(
obs_trajs[k],
"s e ... -> (s e) ...",
)
obs_ts_k = torch.split(obs_k, self.logprob_batch_size, dim=0)
for i, obs_t in enumerate(obs_ts_k):
obs_ts[i][k] = obs_t
values_trajs = np.empty((0, self.n_envs))
for obs in obs_ts:
values = (
self.model.critic(obs, no_augment=True)
.cpu()
.numpy()
.flatten()
)
values_trajs = np.vstack(
(values_trajs, values.reshape(-1, self.n_envs))
)
chains_t = einops.rearrange(
torch.from_numpy(chains_trajs).float().to(self.device),
"s e t h d -> (s e) t h d",
)
chains_ts = torch.split(chains_t, self.logprob_batch_size, dim=0)
logprobs_trajs = np.empty(
(
0,
self.model.ft_denoising_steps,
self.horizon_steps,
self.action_dim,
)
)
for obs, chains in zip(obs_ts, chains_ts):
logprobs = self.model.get_logprobs(obs, chains).cpu().numpy()
logprobs_trajs = np.vstack(
(
logprobs_trajs,
logprobs.reshape(-1, *logprobs_trajs.shape[1:]),
)
)
# normalize reward with running variance if specified
if self.reward_scale_running:
reward_trajs_transpose = self.running_reward_scaler(
reward=reward_trajs.T, first=firsts_trajs[:-1].T
)
reward_trajs = reward_trajs_transpose.T
# bootstrap value with GAE if not done - apply reward scaling with constant if specified
obs_venv_ts = {
key: torch.from_numpy(obs_venv[key]).float().to(self.device)
for key in self.obs_dims.keys()
}
with torch.no_grad():
next_value = (
self.model.critic(obs_venv_ts, no_augment=True)
.reshape(1, -1)
.cpu()
.numpy()
)
advantages_trajs = np.zeros_like(reward_trajs)
lastgaelam = 0
for t in reversed(range(self.n_steps)):
if t == self.n_steps - 1:
nextnonterminal = 1.0 - done_venv
nextvalues = next_value
else:
nextnonterminal = 1.0 - dones_trajs[t + 1]
nextvalues = values_trajs[t + 1]
# delta = r + gamma*V(st+1) - V(st)
delta = (
reward_trajs[t] * self.reward_scale_const
+ self.gamma * nextvalues * nextnonterminal
- values_trajs[t]
)
# A = delta_t + gamma*lamdba*delta_{t+1} + ...
advantages_trajs[t] = lastgaelam = (
delta
+ self.gamma
* self.gae_lambda
* nextnonterminal
* lastgaelam
)
returns_trajs = advantages_trajs + values_trajs
# k for environment step
obs_k = {
k: einops.rearrange(
obs_trajs[k],
"s e ... -> (s e) ...",
)
for k in obs_trajs.keys()
}
chains_k = einops.rearrange(
torch.tensor(chains_trajs).float().to(self.device),
"s e t h d -> (s e) t h d",
)
returns_k = (
torch.tensor(returns_trajs).float().to(self.device).reshape(-1)
)
values_k = (
torch.tensor(values_trajs).float().to(self.device).reshape(-1)
)
advantages_k = (
torch.tensor(advantages_trajs).float().to(self.device).reshape(-1)
)
logprobs_k = torch.tensor(logprobs_trajs).float().to(self.device)
# Update policy and critic
total_steps = self.n_steps * self.n_envs
inds_k = np.arange(total_steps)
clipfracs = []
for update_epoch in range(self.update_epochs):
# for each epoch, go through all data in batches
flag_break = False
np.random.shuffle(inds_k)
num_batch = max(1, total_steps // self.batch_size) # skip last ones
for batch in range(num_batch):
start = batch * self.batch_size
end = start + self.batch_size
inds_b = inds_k[start:end] # b for batch
obs_b = {k: obs_k[k][inds_b] for k in obs_k.keys()}
chains_b = chains_k[inds_b]
returns_b = returns_k[inds_b]
values_b = values_k[inds_b]
advantages_b = advantages_k[inds_b]
logprobs_b = logprobs_k[inds_b]
# get loss
(
pg_loss,
entropy_loss,
v_loss,
clipfrac,
approx_kl,
ratio,
bc_loss,
eta,
) = self.model.loss(
obs_b,
chains_b,
returns_b,
values_b,
advantages_b,
logprobs_b,
use_bc_loss=self.use_bc_loss,
reward_horizon=self.reward_horizon,
)
loss = (
pg_loss
+ entropy_loss * self.ent_coef
+ v_loss * self.vf_coef
+ bc_loss * self.bc_loss_coeff
)
clipfracs += [clipfrac]
# update policy and critic
loss.backward()
if (batch + 1) % self.grad_accumulate == 0:
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor_ft.parameters(),
self.max_grad_norm,
)
self.actor_optimizer.step()
if (
self.learn_eta
and batch % self.eta_update_interval == 0
):
self.eta_optimizer.step()
self.critic_optimizer.step()
self.actor_optimizer.zero_grad()
self.critic_optimizer.zero_grad()
if self.learn_eta:
self.eta_optimizer.zero_grad()
log.info(f"run grad update at batch {batch}")
log.info(
f"approx_kl: {approx_kl}, update_epoch: {update_epoch}, num_batch: {num_batch}"
)
# Stop gradient update if KL difference reaches target
if (
self.target_kl is not None
and approx_kl > self.target_kl
and self.itr >= self.n_critic_warmup_itr
):
flag_break = True
break
if flag_break:
break
# Explained variation of future rewards using value function
y_pred, y_true = values_k.cpu().numpy(), returns_k.cpu().numpy()
var_y = np.var(y_true)
explained_var = (
np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
)
# Update lr
if self.itr >= self.n_critic_warmup_itr:
self.actor_lr_scheduler.step()
if self.learn_eta:
self.eta_lr_scheduler.step()
self.critic_lr_scheduler.step()
self.model.step()
diffusion_min_sampling_std = self.model.get_min_sampling_denoising_std()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | pg loss {pg_loss:8.4f} | value loss {v_loss:8.4f} | bc loss {bc_loss:8.4f} | reward {avg_episode_reward:8.4f} | eta {eta:8.4f} | t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"pg loss": pg_loss,
"value loss": v_loss,
"bc loss": bc_loss,
"eta": eta,
"approx kl": approx_kl,
"ratio": ratio,
"clipfrac": np.mean(clipfracs),
"explained variance": explained_var,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
"diffusion - min sampling std": diffusion_min_sampling_std,
"actor lr": self.actor_optimizer.param_groups[0]["lr"],
"critic lr": self.critic_optimizer.param_groups[0][
"lr"
],
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["pg_loss"] = pg_loss
run_results[-1]["value_loss"] = v_loss
run_results[-1]["bc_loss"] = bc_loss
run_results[-1]["eta"] = eta
run_results[-1]["approx_kl"] = approx_kl
run_results[-1]["ratio"] = ratio
run_results[-1]["clip_frac"] = np.mean(clipfracs)
run_results[-1]["explained_variance"] = explained_var
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
@@ -0,0 +1,405 @@
"""
Use diffusion exact likelihood for policy gradient.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
log = logging.getLogger(__name__)
from util.timer import Timer
from agent.finetune.train_ppo_diffusion_agent import TrainPPODiffusionAgent
class TrainPPOExactDiffusionAgent(TrainPPODiffusionAgent):
def __init__(self, cfg):
super().__init__(cfg)
def run(self):
"""
For exact likelihood, we do not need to save the chains.
"""
# Start training loop
timer = Timer()
run_results = []
last_itr_eval = False
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
last_itr_eval = eval_mode
# Reset env before iteration starts (1) if specified, (2) at eval mode, or (3) right after eval mode
dones_trajs = np.empty((0, self.n_envs))
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
# Holder
obs_trajs = np.empty((0, self.n_envs, self.n_cond_step, self.obs_dim))
samples_trajs = np.empty(
(
0,
self.n_envs,
self.horizon_steps,
self.action_dim,
)
)
chains_trajs = np.empty(
(
0,
self.n_envs,
self.model.ft_denoising_steps + 1,
self.horizon_steps,
self.action_dim,
)
)
reward_trajs = np.empty((0, self.n_envs))
obs_full_trajs = np.empty((0, self.n_envs, self.obs_dim))
obs_full_trajs = np.vstack(
(obs_full_trajs, prev_obs_venv[None].squeeze(2))
) # remove cond_step dim
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = self.model(
cond=torch.from_numpy(prev_obs_venv).float().to(self.device),
deterministic=eval_mode,
return_chain=True,
)
output_venv = (
samples.trajectories.cpu().numpy()
) # n_env x horizon x act
chains_venv = (
samples.chains.cpu().numpy()
) # n_env x denoising x horizon x act
action_venv = output_venv[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
if self.save_full_observations:
obs_full_venv = np.vstack(
[info["full_obs"][None] for info in info_venv]
) # n_envs x n_act_steps x obs_dim
obs_full_trajs = np.vstack(
(obs_full_trajs, obs_full_venv.transpose(1, 0, 2))
)
obs_trajs = np.vstack((obs_trajs, prev_obs_venv[None]))
chains_trajs = np.vstack((chains_trajs, chains_venv[None]))
samples_trajs = np.vstack((samples_trajs, output_venv[None]))
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
dones_trajs = np.vstack((dones_trajs, done_venv[None]))
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
with torch.no_grad():
# Calculate value and logprobs - split into batches to prevent out of memory
obs_t = einops.rearrange(
torch.from_numpy(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
obs_ts = torch.split(obs_t, self.logprob_batch_size, dim=0)
values_trajs = np.empty((0, self.n_envs))
for obs in obs_ts:
values = self.model.critic(obs).cpu().numpy().flatten()
values_trajs = np.vstack(
(values_trajs, values.reshape(-1, self.n_envs))
)
samples_t = einops.rearrange(
torch.from_numpy(samples_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
samples_ts = torch.split(samples_t, self.logprob_batch_size, dim=0)
logprobs_trajs = np.empty((0))
for obs, samples in zip(obs_ts, samples_ts):
logprobs = (
self.model.get_exact_logprobs(obs, samples).cpu().numpy()
)
logprobs_trajs = np.concatenate((logprobs_trajs, logprobs))
# normalize reward with running variance if specified
if self.reward_scale_running:
reward_trajs_transpose = self.running_reward_scaler(
reward=reward_trajs.T, first=firsts_trajs[:-1].T
)
reward_trajs = reward_trajs_transpose.T
# bootstrap value with GAE if not done - apply reward scaling with constant if specified
obs_venv_ts = torch.from_numpy(obs_venv).float().to(self.device)
with torch.no_grad():
next_value = (
self.model.critic(obs_venv_ts).reshape(1, -1).cpu().numpy()
)
advantages_trajs = np.zeros_like(reward_trajs)
lastgaelam = 0
for t in reversed(range(self.n_steps)):
if t == self.n_steps - 1:
nextnonterminal = 1.0 - done_venv
nextvalues = next_value
else:
nextnonterminal = 1.0 - dones_trajs[t + 1]
nextvalues = values_trajs[t + 1]
# delta = r + gamma*V(st+1) - V(st)
delta = (
reward_trajs[t] * self.reward_scale_const
+ self.gamma * nextvalues * nextnonterminal
- values_trajs[t]
)
# A = delta_t + gamma*lamdba*delta_{t+1} + ...
advantages_trajs[t] = lastgaelam = (
delta
+ self.gamma
* self.gae_lambda
* nextnonterminal
* lastgaelam
)
returns_trajs = advantages_trajs + values_trajs
# k for environment step
obs_k = einops.rearrange(
torch.tensor(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
samples_k = einops.rearrange(
torch.tensor(samples_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
returns_k = (
torch.tensor(returns_trajs).float().to(self.device).reshape(-1)
)
values_k = (
torch.tensor(values_trajs).float().to(self.device).reshape(-1)
)
advantages_k = (
torch.tensor(advantages_trajs).float().to(self.device).reshape(-1)
)
logprobs_k = torch.tensor(logprobs_trajs).float().to(self.device)
# Update policy and critic
total_steps = self.n_steps * self.n_envs
inds_k = np.arange(total_steps)
clipfracs = []
for update_epoch in range(self.update_epochs):
# for each epoch, go through all data in batches
flag_break = False
np.random.shuffle(inds_k)
num_batch = max(1, total_steps // self.batch_size) # skip last ones
for batch in range(num_batch):
start = batch * self.batch_size
end = start + self.batch_size
inds_b = inds_k[start:end] # b for batch
obs_b = obs_k[inds_b]
samples_b = samples_k[inds_b]
returns_b = returns_k[inds_b]
values_b = values_k[inds_b]
advantages_b = advantages_k[inds_b]
logprobs_b = logprobs_k[inds_b]
# get loss
(
pg_loss,
v_loss,
clipfrac,
approx_kl,
ratio,
bc_loss,
) = self.model.loss(
obs_b,
samples_b,
returns_b,
values_b,
advantages_b,
logprobs_b,
use_bc_loss=self.use_bc_loss,
reward_horizon=self.reward_horizon,
)
loss = (
pg_loss
+ v_loss * self.vf_coef
+ bc_loss * self.bc_loss_coeff
)
clipfracs += [clipfrac]
# update policy and critic
self.actor_optimizer.zero_grad()
self.critic_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor_ft.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
self.critic_optimizer.step()
log.info(
f"approx_kl: {approx_kl}, update_epoch: {update_epoch}, num_batch: {num_batch}"
)
# Stop gradient update if KL difference reaches target
if self.target_kl is not None and approx_kl > self.target_kl:
flag_break = True
break
if flag_break:
break
# Explained variation of future rewards using value function
y_pred, y_true = values_k.cpu().numpy(), returns_k.cpu().numpy()
var_y = np.var(y_true)
explained_var = (
np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
)
# Plot state trajectories
if (
self.itr % self.render_freq == 0
and self.n_render > 0
and self.traj_plotter is not None
):
self.traj_plotter(
obs_full_trajs=obs_full_trajs,
n_render=self.n_render,
max_episode_steps=self.max_episode_steps,
render_dir=self.render_dir,
itr=self.itr,
)
# Update lr
if self.itr >= self.n_critic_warmup_itr:
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.save_trajs:
run_results[-1]["obs_full_trajs"] = obs_full_trajs
run_results[-1]["obs_trajs"] = obs_trajs
run_results[-1]["action_trajs"] = samples_trajs
run_results[-1]["chains_trajs"] = chains_trajs
run_results[-1]["reward_trajs"] = reward_trajs
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | pg loss {pg_loss:8.4f} | value loss {v_loss:8.4f} | reward {avg_episode_reward:8.4f} | t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"pg loss": pg_loss,
"value loss": v_loss,
"approx kl": approx_kl,
"ratio": ratio,
"clipfrac": np.mean(clipfracs),
"explained variance": explained_var,
"avg episode reward - train": avg_episode_reward,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["pg_loss"] = pg_loss
run_results[-1]["value_loss"] = v_loss
run_results[-1]["approx_kl"] = approx_kl
run_results[-1]["ratio"] = ratio
run_results[-1]["clip_frac"] = np.mean(clipfracs)
run_results[-1]["explained_variance"] = explained_var
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
+404
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@@ -0,0 +1,404 @@
"""
PPO training for Gaussian/GMM policy.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
log = logging.getLogger(__name__)
from util.timer import Timer
from agent.finetune.train_ppo_agent import TrainPPOAgent
class TrainPPOGaussianAgent(TrainPPOAgent):
def __init__(self, cfg):
super().__init__(cfg)
def run(self):
# Start training loop
timer = Timer()
run_results = []
last_itr_eval = False
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
last_itr_eval = eval_mode
# Reset env before iteration starts (1) if specified, (2) at eval mode, or (3) right after eval mode
dones_trajs = np.empty((0, self.n_envs))
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
# Holder
obs_trajs = np.empty((0, self.n_envs, self.n_cond_step, self.obs_dim))
samples_trajs = np.empty(
(
0,
self.n_envs,
self.horizon_steps,
self.action_dim,
)
)
reward_trajs = np.empty((0, self.n_envs))
obs_full_trajs = np.empty((0, self.n_envs, self.obs_dim))
obs_full_trajs = np.vstack(
(obs_full_trajs, prev_obs_venv[None].squeeze(2))
) # remove cond_step dim
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = self.model(
cond=torch.from_numpy(prev_obs_venv).float().to(self.device),
deterministic=eval_mode,
)
output_venv = samples.cpu().numpy()
action_venv = output_venv[:, : self.act_steps, : self.action_dim]
obs_trajs = np.vstack((obs_trajs, prev_obs_venv[None]))
samples_trajs = np.vstack((samples_trajs, output_venv[None]))
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
if self.save_full_observations:
obs_full_venv = np.vstack(
[info["full_obs"][None] for info in info_venv]
) # n_envs x n_act_steps x obs_dim
obs_full_trajs = np.vstack(
(obs_full_trajs, obs_full_venv.transpose(1, 0, 2))
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
dones_trajs = np.vstack((dones_trajs, done_venv[None]))
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
if (
self.furniture_sparse_reward
): # only for furniture tasks, where reward only occurs in one env step
episode_best_reward = episode_reward
else:
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
with torch.no_grad():
# Calculate value and logprobs - split into batches to prevent out of memory
obs_t = einops.rearrange(
torch.from_numpy(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
obs_ts = torch.split(obs_t, self.logprob_batch_size, dim=0)
values_trajs = np.empty((0, self.n_envs))
for obs in obs_ts:
values = self.model.critic(obs).cpu().numpy().flatten()
values_trajs = np.vstack(
(values_trajs, values.reshape(-1, self.n_envs))
)
samples_t = einops.rearrange(
torch.from_numpy(samples_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
samples_ts = torch.split(samples_t, self.logprob_batch_size, dim=0)
logprobs_trajs = np.empty((0))
for obs_t, samples_t in zip(obs_ts, samples_ts):
logprobs = (
self.model.get_logprobs(obs_t, samples_t)[0].cpu().numpy()
)
logprobs_trajs = np.concatenate(
(
logprobs_trajs,
logprobs.reshape(-1),
)
)
# normalize reward with running variance if specified
if self.reward_scale_running:
reward_trajs_transpose = self.running_reward_scaler(
reward=reward_trajs.T, first=firsts_trajs[:-1].T
)
reward_trajs = reward_trajs_transpose.T
# bootstrap value with GAE if not done - apply reward scaling with constant if specified
obs_venv_ts = torch.from_numpy(obs_venv).float().to(self.device)
with torch.no_grad():
next_value = (
self.model.critic(obs_venv_ts).reshape(1, -1).cpu().numpy()
)
advantages_trajs = np.zeros_like(reward_trajs)
lastgaelam = 0
for t in reversed(range(self.n_steps)):
if t == self.n_steps - 1:
nextnonterminal = 1.0 - done_venv
nextvalues = next_value
else:
nextnonterminal = 1.0 - dones_trajs[t + 1]
nextvalues = values_trajs[t + 1]
# delta = r + gamma*V(st+1) - V(st)
delta = (
reward_trajs[t] * self.reward_scale_const
+ self.gamma * nextvalues * nextnonterminal
- values_trajs[t]
)
# A = delta_t + gamma*lamdba*delta_{t+1} + ...
advantages_trajs[t] = lastgaelam = (
delta
+ self.gamma
* self.gae_lambda
* nextnonterminal
* lastgaelam
)
returns_trajs = advantages_trajs + values_trajs
# k for environment step
obs_k = einops.rearrange(
torch.tensor(obs_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
samples_k = einops.rearrange(
torch.tensor(samples_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
returns_k = (
torch.tensor(returns_trajs).float().to(self.device).reshape(-1)
)
values_k = (
torch.tensor(values_trajs).float().to(self.device).reshape(-1)
)
advantages_k = (
torch.tensor(advantages_trajs).float().to(self.device).reshape(-1)
)
logprobs_k = (
torch.tensor(logprobs_trajs).float().to(self.device).reshape(-1)
)
# Update policy and critic
total_steps = self.n_steps * self.n_envs
inds_k = np.arange(total_steps)
clipfracs = []
for update_epoch in range(self.update_epochs):
# for each epoch, go through all data in batches
flag_break = False
np.random.shuffle(inds_k)
num_batch = max(1, total_steps // self.batch_size) # skip last ones
for batch in range(num_batch):
start = batch * self.batch_size
end = start + self.batch_size
inds_b = inds_k[start:end] # b for batch
obs_b = obs_k[inds_b]
samples_b = samples_k[inds_b]
returns_b = returns_k[inds_b]
values_b = values_k[inds_b]
advantages_b = advantages_k[inds_b]
logprobs_b = logprobs_k[inds_b]
# get loss
(
pg_loss,
entropy_loss,
v_loss,
clipfrac,
approx_kl,
ratio,
bc_loss,
std,
) = self.model.loss(
obs_b,
samples_b,
returns_b,
values_b,
advantages_b,
logprobs_b,
use_bc_loss=self.use_bc_loss,
)
loss = (
pg_loss
+ entropy_loss * self.ent_coef
+ v_loss * self.vf_coef
+ bc_loss * self.bc_loss_coeff
)
clipfracs += [clipfrac]
# update policy and critic
self.actor_optimizer.zero_grad()
self.critic_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor_ft.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
self.critic_optimizer.step()
log.info(
f"approx_kl: {approx_kl}, update_epoch: {update_epoch}, num_batch: {num_batch}"
)
# Stop gradient update if KL difference reaches target
if self.target_kl is not None and approx_kl > self.target_kl:
flag_break = True
break
if flag_break:
break
# Explained variation of future rewards using value function
y_pred, y_true = values_k.cpu().numpy(), returns_k.cpu().numpy()
var_y = np.var(y_true)
explained_var = (
np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
)
# Plot state trajectories
if (
self.itr % self.render_freq == 0
and self.n_render > 0
and self.traj_plotter is not None
):
self.traj_plotter(
obs_full_trajs=obs_full_trajs,
n_render=self.n_render,
max_episode_steps=self.max_episode_steps,
render_dir=self.render_dir,
itr=self.itr,
)
# Update lr
if self.itr >= self.n_critic_warmup_itr:
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.save_trajs:
run_results[-1]["obs_full_trajs"] = obs_full_trajs
run_results[-1]["obs_trajs"] = obs_trajs
run_results[-1]["action_trajs"] = samples_trajs
run_results[-1]["reward_trajs"] = reward_trajs
if self.itr % self.log_freq == 0:
time = timer()
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | pg loss {pg_loss:8.4f} | value loss {v_loss:8.4f} | ent {-entropy_loss:8.4f} | reward {avg_episode_reward:8.4f} | t:{time:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"pg loss": pg_loss,
"value loss": v_loss,
"entropy": -entropy_loss,
"std": std,
"approx kl": approx_kl,
"ratio": ratio,
"clipfrac": np.mean(clipfracs),
"explained variance": explained_var,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["pg_loss"] = pg_loss
run_results[-1]["value_loss"] = v_loss
run_results[-1]["entropy_loss"] = entropy_loss
run_results[-1]["approx_kl"] = approx_kl
run_results[-1]["ratio"] = ratio
run_results[-1]["clip_frac"] = np.mean(clipfracs)
run_results[-1]["explained_variance"] = explained_var
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = time
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
@@ -0,0 +1,443 @@
"""
PPO training for Gaussian/GMM policy with pixel observations.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
import math
log = logging.getLogger(__name__)
from util.timer import Timer
from agent.finetune.train_ppo_gaussian_agent import TrainPPOGaussianAgent
from model.common.modules import RandomShiftsAug
class TrainPPOImgGaussianAgent(TrainPPOGaussianAgent):
def __init__(self, cfg):
super().__init__(cfg)
# Image randomization
self.augment = cfg.train.augment
if self.augment:
self.aug = RandomShiftsAug(pad=4)
# Set obs dim - we will save the different obs in batch in a dict
shape_meta = cfg.shape_meta
self.obs_dims = {k: shape_meta.obs[k]["shape"] for k in shape_meta.obs.keys()}
# Gradient accumulation to deal with large GPU RAM usage
self.grad_accumulate = cfg.train.grad_accumulate
def run(self):
# Start training loop
timer = Timer()
run_results = []
last_itr_eval = False
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
last_itr_eval = eval_mode
# Reset env before iteration starts (1) if specified, (2) at eval mode, or (3) right after eval mode
dones_trajs = np.empty((0, self.n_envs))
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
# Holder
obs_trajs = {
k: np.empty((0, self.n_envs, self.n_cond_step, *self.obs_dims[k]))
for k in self.obs_dims
}
samples_trajs = np.empty(
(
0,
self.n_envs,
self.horizon_steps,
self.action_dim,
)
)
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
cond = {
key: torch.from_numpy(prev_obs_venv[key])
.float()
.to(self.device)
for key in self.obs_dims.keys()
} # batch each type of obs and put into dict
samples = self.model(
cond=cond,
deterministic=eval_mode,
)
output_venv = samples.cpu().numpy()
action_venv = output_venv[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
for k in obs_trajs.keys():
obs_trajs[k] = np.vstack((obs_trajs[k], prev_obs_venv[k][None]))
samples_trajs = np.vstack((samples_trajs, output_venv[None]))
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
dones_trajs = np.vstack((dones_trajs, done_venv[None]))
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
with torch.no_grad():
# apply image randomization
obs_trajs["rgb"] = (
torch.from_numpy(obs_trajs["rgb"]).float().to(self.device)
)
obs_trajs["state"] = (
torch.from_numpy(obs_trajs["state"]).float().to(self.device)
)
if self.augment:
rgb = einops.rearrange(
obs_trajs["rgb"],
"s e t c h w -> (s e t) c h w",
)
rgb = self.aug(rgb)
obs_trajs["rgb"] = einops.rearrange(
rgb,
"(s e t) c h w -> s e t c h w",
s=self.n_steps,
e=self.n_envs,
)
# Calculate value and logprobs - split into batches to prevent out of memory
num_split = math.ceil(
self.n_envs * self.n_steps / self.logprob_batch_size
)
obs_ts = [{} for _ in range(num_split)]
for k in obs_trajs.keys():
obs_k = einops.rearrange(
obs_trajs[k],
"s e ... -> (s e) ...",
)
obs_ts_k = torch.split(obs_k, self.logprob_batch_size, dim=0)
for i, obs_t in enumerate(obs_ts_k):
obs_ts[i][k] = obs_t
values_trajs = np.empty((0, self.n_envs))
for obs in obs_ts:
values = (
self.model.critic(obs, no_augment=True)
.cpu()
.numpy()
.flatten()
)
values_trajs = np.vstack(
(values_trajs, values.reshape(-1, self.n_envs))
)
samples_t = einops.rearrange(
torch.from_numpy(samples_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
samples_ts = torch.split(samples_t, self.logprob_batch_size, dim=0)
logprobs_trajs = np.empty((0))
for obs_t, samples_t in zip(obs_ts, samples_ts):
logprobs = (
self.model.get_logprobs(obs_t, samples_t)[0].cpu().numpy()
)
logprobs_trajs = np.concatenate(
(
logprobs_trajs,
logprobs.reshape(-1),
)
)
# normalize reward with running variance if specified
if self.reward_scale_running:
reward_trajs_transpose = self.running_reward_scaler(
reward=reward_trajs.T, first=firsts_trajs[:-1].T
)
reward_trajs = reward_trajs_transpose.T
# bootstrap value with GAE if not done - apply reward scaling with constant if specified
obs_venv_ts = {
key: torch.from_numpy(obs_venv[key]).float().to(self.device)
for key in self.obs_dims.keys()
}
with torch.no_grad():
next_value = (
self.model.critic(obs_venv_ts, no_augment=True)
.reshape(1, -1)
.cpu()
.numpy()
)
advantages_trajs = np.zeros_like(reward_trajs)
lastgaelam = 0
for t in reversed(range(self.n_steps)):
if t == self.n_steps - 1:
nextnonterminal = 1.0 - done_venv
nextvalues = next_value
else:
nextnonterminal = 1.0 - dones_trajs[t + 1]
nextvalues = values_trajs[t + 1]
# delta = r + gamma*V(st+1) - V(st)
delta = (
reward_trajs[t] * self.reward_scale_const
+ self.gamma * nextvalues * nextnonterminal
- values_trajs[t]
)
# A = delta_t + gamma*lamdba*delta_{t+1} + ...
advantages_trajs[t] = lastgaelam = (
delta
+ self.gamma
* self.gae_lambda
* nextnonterminal
* lastgaelam
)
returns_trajs = advantages_trajs + values_trajs
# k for environment step
obs_k = {
k: einops.rearrange(
obs_trajs[k],
"s e ... -> (s e) ...",
)
for k in obs_trajs.keys()
}
samples_k = einops.rearrange(
torch.tensor(samples_trajs).float().to(self.device),
"s e h d -> (s e) h d",
)
returns_k = (
torch.tensor(returns_trajs).float().to(self.device).reshape(-1)
)
values_k = (
torch.tensor(values_trajs).float().to(self.device).reshape(-1)
)
advantages_k = (
torch.tensor(advantages_trajs).float().to(self.device).reshape(-1)
)
logprobs_k = torch.tensor(logprobs_trajs).float().to(self.device)
# Update policy and critic
total_steps = self.n_steps * self.n_envs
inds_k = np.arange(total_steps)
clipfracs = []
for update_epoch in range(self.update_epochs):
# for each epoch, go through all data in batches
flag_break = False
np.random.shuffle(inds_k)
num_batch = max(1, total_steps // self.batch_size) # skip last ones
for batch in range(num_batch):
start = batch * self.batch_size
end = start + self.batch_size
inds_b = inds_k[start:end] # b for batch
obs_b = {k: obs_k[k][inds_b] for k in obs_k.keys()}
samples_b = samples_k[inds_b]
returns_b = returns_k[inds_b]
values_b = values_k[inds_b]
advantages_b = advantages_k[inds_b]
logprobs_b = logprobs_k[inds_b]
# get loss
(
pg_loss,
entropy_loss,
v_loss,
clipfrac,
approx_kl,
ratio,
bc_loss,
std,
) = self.model.loss(
obs_b,
samples_b,
returns_b,
values_b,
advantages_b,
logprobs_b,
use_bc_loss=self.use_bc_loss,
)
loss = (
pg_loss
+ entropy_loss * self.ent_coef
+ v_loss * self.vf_coef
+ bc_loss * self.bc_loss_coeff
)
clipfracs += [clipfrac]
# update policy and critic
loss.backward()
if (batch + 1) % self.grad_accumulate == 0:
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor_ft.parameters(),
self.max_grad_norm,
)
self.actor_optimizer.step()
self.critic_optimizer.step()
self.actor_optimizer.zero_grad()
self.critic_optimizer.zero_grad()
log.info(f"run grad update at batch {batch}")
log.info(
f"approx_kl: {approx_kl}, update_epoch: {update_epoch}, num_batch: {num_batch}"
)
# Stop gradient update if KL difference reaches target
if (
self.target_kl is not None
and approx_kl > self.target_kl
and self.itr >= self.n_critic_warmup_itr
):
flag_break = True
break
if flag_break:
break
# Explained variation of future rewards using value function
y_pred, y_true = values_k.cpu().numpy(), returns_k.cpu().numpy()
var_y = np.var(y_true)
explained_var = (
np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
)
# Update lr
if self.itr >= self.n_critic_warmup_itr:
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | pg loss {pg_loss:8.4f} | value loss {v_loss:8.4f} | bc loss {bc_loss:8.4f} | reward {avg_episode_reward:8.4f} | t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"pg loss": pg_loss,
"value loss": v_loss,
"bc loss": bc_loss,
"std": std,
"approx kl": approx_kl,
"ratio": ratio,
"clipfrac": np.mean(clipfracs),
"explained variance": explained_var,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
"actor lr": self.actor_optimizer.param_groups[0]["lr"],
"critic lr": self.critic_optimizer.param_groups[0][
"lr"
],
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["pg_loss"] = pg_loss
run_results[-1]["value_loss"] = v_loss
run_results[-1]["bc_loss"] = bc_loss
run_results[-1]["std"] = std
run_results[-1]["approx_kl"] = approx_kl
run_results[-1]["ratio"] = ratio
run_results[-1]["clip_frac"] = np.mean(clipfracs)
run_results[-1]["explained_variance"] = explained_var
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
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"""
QSM (Q-Score Matching) for diffusion policy.
"""
import os
import pickle
import einops
import numpy as np
import torch
import logging
import wandb
from copy import deepcopy
log = logging.getLogger(__name__)
from util.timer import Timer
from collections import deque
from agent.finetune.train_agent import TrainAgent
from util.scheduler import CosineAnnealingWarmupRestarts
class TrainQSMDiffusionAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Wwarm up period for critic before actor updates
self.n_critic_warmup_itr = cfg.train.n_critic_warmup_itr
# Optimizer
self.actor_optimizer = torch.optim.AdamW(
self.model.actor.parameters(),
lr=cfg.train.actor_lr,
weight_decay=cfg.train.actor_weight_decay,
)
self.actor_lr_scheduler = CosineAnnealingWarmupRestarts(
self.actor_optimizer,
first_cycle_steps=cfg.train.actor_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.actor_lr,
min_lr=cfg.train.actor_lr_scheduler.min_lr,
warmup_steps=cfg.train.actor_lr_scheduler.warmup_steps,
gamma=1.0,
)
self.critic_optimizer = torch.optim.AdamW(
self.model.critic_q.parameters(),
lr=cfg.train.critic_lr,
weight_decay=cfg.train.critic_weight_decay,
)
self.critic_lr_scheduler = CosineAnnealingWarmupRestarts(
self.critic_optimizer,
first_cycle_steps=cfg.train.critic_lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.critic_lr,
min_lr=cfg.train.critic_lr_scheduler.min_lr,
warmup_steps=cfg.train.critic_lr_scheduler.warmup_steps,
gamma=1.0,
)
# Buffer size
self.buffer_size = cfg.train.buffer_size
# Scaling reward
self.scale_reward_factor = cfg.train.scale_reward_factor
# Updates
self.replay_ratio = cfg.train.replay_ratio
self.critic_tau = cfg.train.critic_tau
self.q_grad_coeff = cfg.train.q_grad_coeff
def run(self):
# make a FIFO replay buffer for obs, action, and reward
obs_buffer = deque(maxlen=self.buffer_size)
action_buffer = deque(maxlen=self.buffer_size)
next_obs_buffer = deque(maxlen=self.buffer_size)
reward_buffer = deque(maxlen=self.buffer_size)
done_buffer = deque(maxlen=self.buffer_size)
first_buffer = deque(maxlen=self.buffer_size)
# Start training loop
timer = Timer()
run_results = []
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
# Reset env at the beginning of an iteration
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
last_itr_eval = eval_mode
reward_trajs = np.empty((0, self.n_envs))
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = (
self.model(
cond=torch.from_numpy(prev_obs_venv)
.float()
.to(self.device),
deterministic=eval_mode,
)
.cpu()
.numpy()
) # n_env x horizon x act
action_venv = samples[:, : self.act_steps]
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
# add to buffer
obs_buffer.append(prev_obs_venv)
action_buffer.append(action_venv)
next_obs_buffer.append(obs_venv)
reward_buffer.append(reward_venv * self.scale_reward_factor)
done_buffer.append(done_venv)
first_buffer.append(firsts_trajs[step])
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
obs_trajs = np.array(deepcopy(obs_buffer))
action_trajs = np.array(deepcopy(action_buffer))
next_obs_trajs = np.array(deepcopy(next_obs_buffer))
reward_trajs = np.array(deepcopy(reward_buffer))
done_trajs = np.array(deepcopy(done_buffer))
first_trajs = np.array(deepcopy(first_buffer))
# flatten
obs_trajs = einops.rearrange(
obs_trajs,
"s e h d -> (s e) h d",
)
next_obs_trajs = einops.rearrange(
next_obs_trajs,
"s e h d -> (s e) h d",
)
action_trajs = einops.rearrange(
action_trajs,
"s e h d -> (s e) h d",
)
reward_trajs = reward_trajs.reshape(-1)
done_trajs = done_trajs.reshape(-1)
first_trajs = first_trajs.reshape(-1)
num_batch = int(
self.n_steps * self.n_envs / self.batch_size * self.replay_ratio
)
for _ in range(num_batch):
# Sample batch
inds = np.random.choice(len(obs_trajs), self.batch_size)
obs_b = torch.from_numpy(obs_trajs[inds]).float().to(self.device)
next_obs_b = (
torch.from_numpy(next_obs_trajs[inds]).float().to(self.device)
)
actions_b = (
torch.from_numpy(action_trajs[inds]).float().to(self.device)
)
reward_b = (
torch.from_numpy(reward_trajs[inds]).float().to(self.device)
)
done_b = torch.from_numpy(done_trajs[inds]).float().to(self.device)
# update critic q function
critic_loss = self.model.loss_critic(
obs_b, next_obs_b, actions_b, reward_b, done_b, self.gamma
)
self.critic_optimizer.zero_grad()
critic_loss.backward()
self.critic_optimizer.step()
# update target q function
self.model.update_target_critic(self.critic_tau)
loss_critic = critic_loss.detach()
# Update policy with collected trajectories
loss = self.model.loss_actor(
obs_b,
actions_b,
self.q_grad_coeff,
)
self.actor_optimizer.zero_grad()
loss.backward()
if self.itr >= self.n_critic_warmup_itr:
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.actor.parameters(), self.max_grad_norm
)
self.actor_optimizer.step()
# Update lr
self.actor_lr_scheduler.step()
self.critic_lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | reward {avg_episode_reward:8.4f} |t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"loss - critic": loss_critic,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["loss_critic"] = loss_critic
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1
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"""
Reward-weighted regression (RWR) for diffusion policy.
"""
import os
import pickle
import numpy as np
import torch
import logging
import wandb
log = logging.getLogger(__name__)
from util.timer import Timer
from agent.finetune.train_agent import TrainAgent
from util.scheduler import CosineAnnealingWarmupRestarts
class TrainRWRDiffusionAgent(TrainAgent):
def __init__(self, cfg):
super().__init__(cfg)
# note the discount factor gamma here is applied to reward every act_steps, instead of every env step
self.gamma = cfg.train.gamma
# Build optimizer
self.optimizer = torch.optim.AdamW(
self.model.parameters(),
lr=cfg.train.lr,
weight_decay=cfg.train.weight_decay,
)
self.lr_scheduler = CosineAnnealingWarmupRestarts(
self.optimizer,
first_cycle_steps=cfg.train.lr_scheduler.first_cycle_steps,
cycle_mult=1.0,
max_lr=cfg.train.lr,
min_lr=cfg.train.lr_scheduler.min_lr,
warmup_steps=cfg.train.lr_scheduler.warmup_steps,
gamma=1.0,
)
# Reward exponential
self.beta = cfg.train.beta
# Max weight for AWR
self.max_reward_weight = cfg.train.max_reward_weight
# Updates
self.update_epochs = cfg.train.update_epochs
def run(self):
# Start training loop
timer = Timer()
run_results = []
done_venv = np.zeros((1, self.n_envs))
while self.itr < self.n_train_itr:
# Prepare video paths for each envs --- only applies for the first set of episodes if allowing reset within iteration and each iteration has multiple episodes from one env
options_venv = [{} for _ in range(self.n_envs)]
if self.itr % self.render_freq == 0 and self.render_video:
for env_ind in range(self.n_render):
options_venv[env_ind]["video_path"] = os.path.join(
self.render_dir, f"itr-{self.itr}_trial-{env_ind}.mp4"
)
# Define train or eval - all envs restart
eval_mode = self.itr % self.val_freq == 0 and not self.force_train
self.model.eval() if eval_mode else self.model.train()
firsts_trajs = np.zeros((self.n_steps + 1, self.n_envs))
# Reset env at the beginning of an iteration
if self.reset_at_iteration or eval_mode or last_itr_eval:
prev_obs_venv = self.reset_env_all(options_venv=options_venv)
firsts_trajs[0] = 1
else:
firsts_trajs[0] = (
done_venv # if done at the end of last iteration, then the envs are just reset
)
last_itr_eval = eval_mode
reward_trajs = np.empty((0, self.n_envs))
# Holders
obs_trajs = np.empty((0, self.n_envs, self.n_cond_step, self.obs_dim))
samples_trajs = np.empty(
(
0,
self.n_envs,
self.horizon_steps,
self.action_dim,
)
)
# Collect a set of trajectories from env
for step in range(self.n_steps):
if step % 10 == 0:
print(f"Processed step {step} of {self.n_steps}")
# Select action
with torch.no_grad():
samples = (
self.model(
cond=torch.from_numpy(prev_obs_venv)
.float()
.to(self.device),
deterministic=eval_mode,
)
.cpu()
.numpy()
) # n_env x horizon x act
action_venv = samples[:, : self.act_steps]
obs_trajs = np.vstack((obs_trajs, prev_obs_venv[None]))
samples_trajs = np.vstack((samples_trajs, samples[None]))
# Apply multi-step action
obs_venv, reward_venv, done_venv, info_venv = self.venv.step(
action_venv
)
reward_trajs = np.vstack((reward_trajs, reward_venv[None]))
firsts_trajs[step + 1] = done_venv
prev_obs_venv = obs_venv
# Summarize episode reward --- this needs to be handled differently depending on whether the environment is reset after each iteration. Only count episodes that finish within the iteration.
episodes_start_end = []
for env_ind in range(self.n_envs):
env_steps = np.where(firsts_trajs[:, env_ind] == 1)[0]
for i in range(len(env_steps) - 1):
start = env_steps[i]
end = env_steps[i + 1]
if end - start > 1:
episodes_start_end.append((env_ind, start, end - 1))
if len(episodes_start_end) > 0:
# Compute transitions for completed trajectories
obs_trajs_split = [
obs_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
samples_trajs_split = [
samples_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
reward_trajs_split = [
reward_trajs[start : end + 1, env_ind]
for env_ind, start, end in episodes_start_end
]
num_episode_finished = len(reward_trajs_split)
# Compute episode returns
discounted_reward_trajs_split = [
[
self.gamma**t * r
for t, r in zip(
list(range(end - start + 1)),
reward_trajs[start : end + 1, env_ind],
)
]
for env_ind, start, end in episodes_start_end
]
returns_trajs_split = [
np.cumsum(y[::-1])[::-1] for y in discounted_reward_trajs_split
]
returns_trajs_split = np.concatenate(returns_trajs_split)
episode_reward = np.array(
[np.sum(reward_traj) for reward_traj in reward_trajs_split]
)
episode_best_reward = np.array(
[
np.max(reward_traj) / self.act_steps
for reward_traj in reward_trajs_split
]
)
avg_episode_reward = np.mean(episode_reward)
avg_best_reward = np.mean(episode_best_reward)
success_rate = np.mean(
episode_best_reward >= self.best_reward_threshold_for_success
)
else:
episode_reward = np.array([])
num_episode_finished = 0
avg_episode_reward = 0
avg_best_reward = 0
success_rate = 0
log.info("[WARNING] No episode completed within the iteration!")
# Update
if not eval_mode:
# Tensorize data and put them to device
# k for environment step
obs_k = (
torch.tensor(np.concatenate(obs_trajs_split))
.float()
.to(self.device)
)
samples_k = (
torch.tensor(np.concatenate(samples_trajs_split))
.float()
.to(self.device)
)
# Normalize reward
returns_trajs_split = (
returns_trajs_split - np.mean(returns_trajs_split)
) / (returns_trajs_split.std() + 1e-3)
rewards_k = (
torch.tensor(returns_trajs_split)
.float()
.to(self.device)
.reshape(-1)
)
rewards_k_scaled = torch.exp(self.beta * rewards_k)
rewards_k_scaled.clamp_(max=self.max_reward_weight)
# rewards_k_scaled = rewards_k_scaled / rewards_k_scaled.mean()
# Update policy and critic
total_steps = len(rewards_k_scaled)
inds_k = np.arange(total_steps)
for _ in range(self.update_epochs):
# for each epoch, go through all data in batches
np.random.shuffle(inds_k)
num_batch = max(1, total_steps // self.batch_size) # skip last ones
for batch in range(num_batch):
start = batch * self.batch_size
end = start + self.batch_size
inds_b = inds_k[start:end] # b for batch
obs_b = obs_k[inds_b]
samples_b = samples_k[inds_b]
rewards_b = rewards_k_scaled[inds_b]
# Update policy with collected trajectories
loss = self.model.loss(
samples_b,
obs_b,
rewards_b,
)
self.optimizer.zero_grad()
loss.backward()
if self.max_grad_norm is not None:
torch.nn.utils.clip_grad_norm_(
self.model.parameters(), self.max_grad_norm
)
self.optimizer.step()
# Update lr
self.lr_scheduler.step()
# Save model
if self.itr % self.save_model_freq == 0 or self.itr == self.n_train_itr - 1:
self.save_model()
# Log loss and save metrics
run_results.append(
{
"itr": self.itr,
}
)
if self.itr % self.log_freq == 0:
if eval_mode:
log.info(
f"eval: success rate {success_rate:8.4f} | avg episode reward {avg_episode_reward:8.4f} | avg best reward {avg_best_reward:8.4f}"
)
if self.use_wandb:
wandb.log(
{
"success rate - eval": success_rate,
"avg episode reward - eval": avg_episode_reward,
"avg best reward - eval": avg_best_reward,
"num episode - eval": num_episode_finished,
},
step=self.itr,
commit=False,
)
run_results[-1]["eval_success_rate"] = success_rate
run_results[-1]["eval_episode_reward"] = avg_episode_reward
run_results[-1]["eval_best_reward"] = avg_best_reward
else:
log.info(
f"{self.itr}: loss {loss:8.4f} | reward {avg_episode_reward:8.4f} |t:{timer():8.4f}"
)
if self.use_wandb:
wandb.log(
{
"loss": loss,
"avg episode reward - train": avg_episode_reward,
"num episode - train": num_episode_finished,
},
step=self.itr,
commit=True,
)
run_results[-1]["loss"] = loss
run_results[-1]["train_episode_reward"] = avg_episode_reward
run_results[-1]["time"] = timer()
with open(self.result_path, "wb") as f:
pickle.dump(run_results, f)
self.itr += 1