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2026SEL3-project-Brittle_St.../src/brittle_star_project/trainers/PPOTrainer.py

991 lines
34 KiB
Python

import datetime
import random
import time
from dataclasses import asdict, dataclass
from functools import partial
from typing import Any, Optional
import jax
import jax.numpy as jnp
import numpy as np
import optax
import flax.linen as nn
from flax.training.train_state import TrainState
from experiment_logger import get_logger
from brittle_star_project.configs.main_config import BrittleStarConfig
from brittle_star_project.dataclasses import EpisodeStatistics
from brittle_star_project.environment.BrittleStarJaxEnvWrapper import BrittleStarJaxEnvWrapper
from brittle_star_project.MLPs.mlps import (
Actor,
AgentParams,
GenericDenseLayersWithActivation,
MessagePasser,
OneDenseLayerMLP,
Storage,
)
from brittle_star_project.ppo import PPO
from brittle_star_project.environment import MorphMode
from brittle_star_project.utils import logged_jit
logger11 = get_logger()
# TODO: move to config
_ALLOWED_OBS_KEYS = {
"joint_position",
"joint_velocity",
"joint_actuator_force",
"actuator_force",
"disk_position",
"disk_rotation",
"disk_linear_velocity",
"disk_angular_velocity",
"unit_xy_direction_to_target",
"xy_distance_to_target",
}
# TODO: clip scaled reward?
def build_adjacency(segments_per_arm, mode: MorphMode):
num_arms = sum(1 for s in segments_per_arm if s > 0)
num_segments = sum(segments_per_arm)
# FOR NOW SEMI HARDCODE:
# CENTRALIZED: 1 agent, no stress, adja = 1,1 = [[1]]
# FULLY CONNECTED: 5 agents: adj = alle 1
# CENTRAL DISK:#arms= 5 agents, only neighbor as adjacent so diagonal kinda..
# ARM = #segments agents: diago kinda, but extra, center ring too, put center mlps first or..
if mode == MorphMode.CENTRALIZED:
return jnp.ones((1, 1))
if mode == MorphMode.FULLY_CONNECTED:
adj = jnp.ones((num_arms, num_arms)) # everybody adjacent everybody
return adj
if mode == MorphMode.RING: # ring
adj = jnp.zeros((num_arms, num_arms))
for i in range(num_arms):
adj = adj.at[i, i].set(1) # self
adj = adj.at[i, (i - 1) % num_arms].set(1)
adj = adj.at[i, (i + 1) % num_arms].set(1) # left and right..
return adj
if mode == MorphMode.SEGMENT:
num_nodes = num_arms + num_segments
adj = jnp.zeros((num_nodes, num_nodes))
# first ring
for i in range(num_arms):
# self
adj = adj.at[i, i].set(1)
# ring neighbors
adj = adj.at[i, (i - 1) % num_arms].set(1)
adj = adj.at[i, (i + 1) % num_arms].set(1)
# then segment chains
idx = 0
for arm_idx, seg_count in enumerate(segments_per_arm):
for i in range(seg_count):
seg_node = num_arms + idx + i
adj = adj.at[seg_node, seg_node].set(1)
if i > 0:
adj = adj.at[seg_node, seg_node - 1].set(1)
if i < seg_count - 1:
adj = adj.at[seg_node, seg_node + 1].set(1)
idx += seg_count
idx = 0
for arm_idx, seg_count in enumerate(segments_per_arm):
first_seg = num_arms + idx # first segment of this arm
# connect ring node first segment
adj = adj.at[arm_idx, first_seg].set(1)
adj = adj.at[first_seg, arm_idx].set(1)
idx += seg_count
return adj
@logged_jit
def _clip_action(action: jnp.ndarray, low: jnp.ndarray, high: jnp.ndarray) -> jnp.ndarray:
return jnp.clip(action, low, high)
def _compute_explained_variance(values: jnp.ndarray, returns: jnp.ndarray) -> float:
var_returns = jnp.var(returns)
explained_var = 1.0 - jnp.var(returns - values) / (var_returns + 1e-8)
return float(explained_var)
@logged_jit
def _linear_schedule(count, minibatch_count, update_epochs, num_iterations, learning_rate):
frac = 1.0 - (count // (minibatch_count * update_epochs)) / num_iterations
return learning_rate * frac
@logged_jit
def _normalize_obs(obs, mean, var, eps=1e-8):
return jnp.clip((obs - mean) / jnp.sqrt(var + eps), -10.0, 10.0)
def _convert_obs_dict_to_array_morphology(obs_dict, morph_mode, segments_per_arm: jnp.ndarray):
num_segments = int(segments_per_arm.sum())
num_arms = int(jnp.where(segments_per_arm > 0, 1, 0).sum())
@logged_jit
def _filter_and_flatten(o) -> jnp.ndarray:
# vmap feeds one env at a time — v has NO batch dim here
# shapes are e.g. (n_features,) or (n_nodes, feat)
values = []
for key in sorted(o.keys()):
if key not in _ALLOWED_OBS_KEYS:
continue
v = o[key]
if v.size == 0:
continue
# -------- CENTRALIZED --------
if morph_mode == MorphMode.CENTRALIZED:
values.append(v.reshape(1, -1)) # (1, feat)
continue
# -------- SPLIT TO SEGMENTS --------
if key in _JOINT_SCALED_KEYS:
if morph_mode == MorphMode.SEGMENT:
center_size = num_arms * 3 * 2
v_center = v[:center_size].reshape(num_arms, 3 * 2) # (arms, 6)
v_segs = v[center_size:].reshape(-1, 2) # (segs, 2)
values.append(jnp.concatenate([v_center, v_segs], axis=0)) # (arms+segs, ?)
continue
v = v.reshape(num_arms, -1) # (n_arms, 2)
elif key in _SEGMENT_SCALED_KEYS:
v = v[:, None] # (segments, 1)
else:
# global key, broadcast to all nodes
n_nodes = (num_segments + num_arms) if morph_mode == MorphMode.SEGMENT else num_arms
v = jnp.repeat(v[None, :], n_nodes, axis=0) # (n_nodes, feat)
# -------- SEGMENT MODE --------
if morph_mode == MorphMode.SEGMENT:
values.append(v) # (n_nodes, feat)
continue
# -------- ARM MODE --------
v = v.reshape(num_arms, -1)
values.append(v) # (n_arms, feat)
return jnp.concatenate(values, axis=-1) # (n_nodes, total_feat)
return jax.vmap(_filter_and_flatten)(obs_dict)
# output: (batch, n_nodes, total_feat)
# Observation keys whose size scales with the number of joints (2 per segment).
_JOINT_SCALED_KEYS = frozenset(
{ # TODO CODE SMELL
"joint_position",
"joint_velocity",
"joint_actuator_force",
"actuator_force",
}
)
# Observation keys whose size scales with the number of segments (1 per segment).
_SEGMENT_SCALED_KEYS = frozenset(
{
"segment_contact",
}
)
# TODO: update to work with extra dimension + message passing
def _get_action_and_value_noise(
sensor: nn.Module,
feature_extractor: nn.Module,
actor: nn.Module,
critic: nn.Module,
message_passer: Optional[nn.Module],
agent_state: TrainState,
next_obs: jnp.ndarray,
key,
action_low,
action_high,
adj_matrix: jnp.ndarray,
):
# (B, n_nodes, feat)
hidden = apply_per_node(sensor, agent_state.params["sensor_params"], next_obs)
get_logger().debug(f"[_get_action_and_value_noise] hidden (before): {hidden.shape}")
if message_passer is not None:
params = agent_state.params["message_passer_params"]
# (n_nodes, feat) --> let each node talk with its neighbours ==> vmap over B dimension
hidden = jax.vmap(lambda x: message_passer.apply(params, x, adj_matrix))(hidden)
get_logger().debug(f"[_get_action_and_value_noise] hidden (after): {hidden.shape}")
hidden_critic = apply_shared(
feature_extractor, agent_state.params["feature_extractor_params"], next_obs
)
mean, log_std = apply_per_node(actor, agent_state.params["actor_params"], hidden)
log_std = jnp.clip(log_std, -5, 2)
key, subkey = jax.random.split(key)
noise = jax.random.normal(subkey, shape=mean.shape)
std = jnp.exp(log_std)
raw_action = mean + noise * std
clipped_action = _clip_action(raw_action, action_low, action_high)
flat_clipped_action = clipped_action.reshape(
clipped_action.shape[0], -1
) # concat the per agent, keep the envs dim (batch, agent * action)
logprob = -0.5 * (((raw_action - mean) / std) ** 2 + 2 * log_std + jnp.log(2 * jnp.pi)).sum(
axis=(-2, -1)
)
value = apply_shared(critic, agent_state.params["critic_params"], hidden_critic)
return flat_clipped_action, raw_action, logprob, value.squeeze(-1), mean, std, key
# TODO: update to work vectorized (sensor, actor, message passer) + message passing
def _step_once(
carry,
_,
env_step_fn,
adj_matrix,
sensor: nn.Module,
feature_extractor: nn.Module,
actor: nn.Module,
critic: nn.Module,
message_passer: Optional[nn.Module],
action_low,
action_high,
):
agent_state, episode_stats, obs, done, key, env_state = carry
flat_clipped_action, raw_action, logprob, value, mean, std, key = _get_action_and_value_noise(
sensor,
feature_extractor,
actor,
critic,
message_passer,
agent_state,
obs,
key,
action_low,
action_high,
adj_matrix,
)
logger11.debug(f"[_step_once] raw_action: {raw_action.shape}")
logger11.debug(f"[_step_once] clipped_action: {flat_clipped_action.shape}")
# Supporting signals (often where mismatch originates)
logger11.debug(f"[_step_once] logprob: {logprob.shape}")
logger11.debug(f"[_step_once] value: {value.shape}")
logger11.debug(f"[_step_once] mean: {mean.shape}")
logger11.debug(f"[_step_once] std: {std.shape}")
# ---- ENV STEP ----
episode_stats, env_state, (next_obs, reward, next_done) = env_step_fn(
episode_stats, env_state, flat_clipped_action
)
logger11.debug(f"[_step_once] next_obs: {next_obs.shape}")
logger11.debug(f"[_step_once] reward: {reward.shape}")
logger11.debug(f"[_step_once] next_done: {next_done.shape}")
storage = Storage(
obs=obs,
actions=raw_action,
raw_actions=raw_action,
logprobs=logprob,
dones=done,
values=value,
rewards=reward,
means=mean,
stds=std,
returns=jnp.zeros_like(reward),
advantages=jnp.zeros_like(reward),
)
return (agent_state, episode_stats, next_obs, next_done, key, env_state), storage
def _reward_fn(env_state, next_env_state):
# if delta distance positive ==> brittle star walking away from target
delta_distance = (
next_env_state.observations["xy_distance_to_target"]
- env_state.observations["xy_distance_to_target"]
).squeeze(-1)
env_reward = next_env_state.reward
clipped_env_reward = jnp.clip(100 * env_reward, -10, 10)
time_penalty = 0.1
distance_penalty = jnp.clip(0.5 * delta_distance, -0.5, 0.5)
penalty = time_penalty + distance_penalty
return jnp.where(next_env_state.terminated, 50.0, clipped_env_reward - penalty)
def _step_env_wrapped(episode_stats, env_state, action, env_step_fn, morph_mode, segments_per_arm):
next_env_state = env_step_fn(env_state, action)
reward = _reward_fn(env_state, next_env_state)
terminated = next_env_state.terminated
truncated = next_env_state.truncated
done = terminated | truncated
new_episode_return = episode_stats.episode_returns + reward
new_episode_length = episode_stats.episode_lengths + 1
episode_stats = episode_stats.replace(
episode_returns=new_episode_return * (1 - done),
episode_lengths=new_episode_length * (1 - done),
returned_episode_returns=jnp.where(
done, new_episode_return, episode_stats.returned_episode_returns
),
returned_episode_lengths=jnp.where(
done, new_episode_length, episode_stats.returned_episode_lengths
),
)
return (
episode_stats,
next_env_state,
(
_convert_obs_dict_to_array_morphology(
next_env_state.observations, morph_mode, segments_per_arm
),
reward,
done,
),
)
def apply_per_node(net, params, x):
# params: (nodes, ...)
# x: (batch, nodes, feat)
def apply_single_node(p, x_node):
# x_node: (batch, feat)
return jax.vmap(lambda xi: net.apply(p, xi))(x_node)
return jax.vmap(apply_single_node, in_axes=(0, 1), out_axes=1)(params, x)
def apply_shared(net, params, x):
# x: (batch, nodes, feat)
# If the critic expects a single vector per environment:
batch_size = x.shape[0]
x_flattened = x.reshape(batch_size, -1)
return jax.vmap(lambda xi: net.apply(params, xi))(x_flattened)
# TODO: update to work with extra dimension + message passing
def _rollout_jit(
agent_state,
episode_stats,
env_state,
next_obs,
next_done,
key,
max_steps,
step_env_fn,
sensor: nn.Module,
feature_extractor: nn.Module,
actor: nn.Module,
critic: nn.Module,
message_passer: Optional[nn.Module],
action_low,
action_high,
adj_matrix,
):
(agent_state, episode_stats, next_obs, next_done, key, env_state), storage = jax.lax.scan(
partial(
_step_once,
sensor=sensor,
feature_extractor=feature_extractor,
actor=actor,
critic=critic,
message_passer=message_passer,
env_step_fn=step_env_fn,
action_low=action_low,
action_high=action_high,
adj_matrix=adj_matrix,
),
(agent_state, episode_stats, next_obs, next_done, key, env_state),
(),
max_steps,
)
return agent_state, episode_stats, next_obs, next_done, storage, key, env_state
def _compute_gae_once(carry, inp, gamma, gae_lambda):
advantages = carry
nextdone, nextvalues, curvalues, reward = inp
nextnonterminal = 1.0 - nextdone
delta = reward + gamma * nextvalues * nextnonterminal - curvalues
advantages = delta + gamma * gae_lambda * nextnonterminal * advantages
return advantages, advantages
def _compute_gae_jit(
agent_state,
storage,
next_obs,
next_done,
gamma,
gae_lambda,
num_envs,
feature_extractor,
critic,
):
next_value = apply_shared(
critic,
agent_state.params["critic_params"],
apply_shared(feature_extractor, agent_state.params["feature_extractor_params"], next_obs),
).squeeze(-1)
advantages = jnp.zeros((num_envs,))
dones = jnp.concatenate([storage.dones, next_done[None, :]], axis=0)
values = jnp.concatenate([storage.values, next_value[None, :]], axis=0)
_, advantages = jax.lax.scan(
partial(_compute_gae_once, gamma=gamma, gae_lambda=gae_lambda),
advantages,
(dones[1:], values[1:], values[:-1], storage.rewards),
reverse=True,
)
returns = advantages + storage.values
advantages = (advantages - advantages.mean()) / (advantages.std() + 1e-8)
return storage.replace(advantages=advantages, returns=returns)
@dataclass
class TrainingMeasurements:
loss: jnp.ndarray
pg_loss: jnp.ndarray
v_loss: jnp.ndarray
entropy_loss: jnp.ndarray
approx_kl: jnp.ndarray
avg_episodic_return: float
explained_variance: float
num_terminated: int
num_truncated: int
avg_terminated_length: Any
avg_truncated_length: Any
class PPOTrainer:
def __init__(
self,
cfg: BrittleStarConfig,
env: BrittleStarJaxEnvWrapper,
run_dir: str,
run_name: str,
):
self.cfg = cfg
self.ppo = cfg.ppo
self.experiment = cfg.experiment
self.logging_cfg = cfg.logging
self.env = env
self.run_dir = run_dir
self.run_name = run_name
self.logger = get_logger()
# Derived runtime fields
self.batch_size = self.ppo.num_envs * self.ppo.num_steps
self.num_iterations = self.ppo.total_timesteps // self.batch_size
self.key = jax.random.PRNGKey(self.experiment.seed)
self.morph_mode = self.cfg.morphology.morph_mode
self.segments_per_arm = jnp.asarray(self.cfg.morphology.segments_per_arm, dtype=jnp.int32)
self.logger.info(f"[INIT]: Used morphology mode {self.morph_mode}")
self.adj = build_adjacency(cfg.morphology.segments_per_arm, self.morph_mode)
(
self.sensor,
self.message_passer,
self.actor,
self.feature_extractor,
self.critic,
self.needed_copies,
) = self._init_agent()
self.sensor.apply = logged_jit(self.sensor.apply)
self.feature_extractor.apply = logged_jit(self.feature_extractor.apply)
self.actor.apply = logged_jit(self.actor.apply)
self.critic.apply = logged_jit(self.critic.apply)
action_low = jnp.asarray(self.env.single_action_space.low, dtype=jnp.float32)
action_high = jnp.asarray(self.env.single_action_space.high, dtype=jnp.float32)
self._rollout_jit = logged_jit(
partial(
_rollout_jit,
max_steps=self.ppo.num_steps,
step_env_fn=partial(
_step_env_wrapped,
env_step_fn=self.env.step,
morph_mode=self.morph_mode,
segments_per_arm=self.segments_per_arm,
),
sensor=self.sensor,
feature_extractor=self.feature_extractor,
actor=self.actor,
critic=self.critic,
message_passer=self.message_passer,
action_low=action_low,
action_high=action_high,
adj_matrix=self.adj,
)
)
self._compute_gae_jit = logged_jit(
partial(
_compute_gae_jit,
num_envs=self.ppo.num_envs,
gamma=self.ppo.gamma,
gae_lambda=self.ppo.gae_lambda,
feature_extractor=self.feature_extractor,
critic=self.critic,
)
)
def apply_sensor(p, x):
return apply_per_node(self.sensor, p, x)
def apply_actor(p, x):
return apply_per_node(self.actor, p, x)
def apply_critic(p, x):
return apply_shared(self.critic, p, x)
def apply_feature(p, x):
return apply_shared(self.feature_extractor, p, x)
def apply_message_passer(p, x):
return apply_shared(self.message_passer, p, x)
self._ppo = PPO(self.ppo, apply_sensor, apply_actor, apply_critic, apply_feature)
self.agent_state = self._init_agent_state()
self.episode_stats = self._init_episode_stats()
self._init_random()
def _init_random(self):
self.logger.info(f"[RANDOM]: Setting random seed to {self.experiment.seed}")
random.seed(self.experiment.seed)
np.random.seed(self.experiment.seed)
def _init_agent(self):
self.logger.info("[AGENT]: Initializing agent...")
match self.morph_mode:
case MorphMode.CENTRALIZED:
needed_copies = 1
case MorphMode.FULLY_CONNECTED | MorphMode.RING:
needed_copies = jnp.where(self.segments_per_arm > 0, 1, 0).sum().item()
case MorphMode.SEGMENT:
needed_copies = (
self.segments_per_arm.sum() + jnp.where(self.segments_per_arm > 0, 1, 0).sum()
).item()
actor = Actor(action_dim=self.env.single_action_space.shape[0])
sensor = GenericDenseLayersWithActivation(layer_sizes=[300, 300, 300])
message_passer: Optional[nn.Module] = (
MessagePasser(
hidden_dim=300,
num_propagation_steps=self.cfg.architecture.message_passing_steps or 4,
)
if self.morph_mode != MorphMode.CENTRALIZED
else None
)
feature_extractor = GenericDenseLayersWithActivation(layer_sizes=[300, 300, 300])
critic = OneDenseLayerMLP()
return sensor, message_passer, actor, feature_extractor, critic, needed_copies
def _init_agent_state(self) -> TrainState:
self.logger.info("[AGENT STATE]: Initializing agent state...")
self.key, sensor_key, actor_key, critic_key, feature_extractor_key, message_passer_key = (
jax.random.split(self.key, 6)
)
dummy_reset = self.env.reset(seed=0)
for k, v in dummy_reset.observations.items():
self.logger.debug(k, v.shape)
sample_obs = _convert_obs_dict_to_array_morphology(
dummy_reset.observations,
self.morph_mode,
self.segments_per_arm,
)[0] # take first env
self.logger.debug(f"[_init_agent_state] sample_obs: {sample_obs.shape}")
self.obs_mean = jnp.zeros((len(sample_obs),))
self.obs_var = jnp.ones((len(sample_obs),))
self.obs_count = 1e-4
self.logger.debug(f"[_init_agent_state] obs_mean: {self.obs_mean.shape}")
self.logger.debug(f"[_init_agent_state] obs_var: {self.obs_var.shape}")
self.logger.debug(f"[_init_agent_state]: Needed copies: {self.needed_copies}")
sensor_keys = jax.random.split(sensor_key, self.needed_copies)
actor_keys = jax.random.split(actor_key, self.needed_copies)
# note: assumed only 1 message passer needed for now
# message_passer_keys = jax.random.split(message_passer_key, self.needed_copies)
# (needed_copies, 175)
sensor_params = jax.vmap(lambda k: self.sensor.init(k, sample_obs))(sensor_keys)
# self.logger.debug(
# f"[_init_agent_state] sensor_params: {jax.tree.map(lambda x: x.shape, sensor_params)}"
# )
single_sensor_param = jax.tree.map(lambda x: x[0], sensor_params)
# self.logger.debug(
# f"[_init_agent_state] single_sensor_param: {
# jax.tree.map(lambda x: x.shape, single_sensor_param)
# }"
# )
sensor_params_sample = self.sensor.apply(single_sensor_param, sample_obs)
self.logger.debug(
f"[_init_agent_state] sensor_params_sample shape: {sensor_params_sample.shape}"
)
actor_params = jax.vmap(lambda k: self.actor.init(k, sensor_params_sample))(actor_keys)
# self.logger.debug(
# f"[_init_agent_state] actor_params: {jax.tree.map(lambda x: x.shape, actor_params)}"
# )
message_passer_params = {}
if self.morph_mode != MorphMode.CENTRALIZED:
assert self.message_passer is not None, "MessagePasser is None"
# message_passer_params = jax.vmap(
# lambda k: self.message_passer.init(
# k, self.sensor.apply(single_sensor_param, sample_obs), self.adj
# )
# )(message_passer_keys)
message_passer_params = self.message_passer.init(
message_passer_key,
self.sensor.apply(single_sensor_param, sample_obs),
self.adj,
)
# self.logger.debug(
# f"[_init_agent_state] message_passer_params: {
# jax.tree.map(lambda x: x.shape, message_passer_params)
# }"
# )
flat_obs = sample_obs.reshape(-1) # BECAUSE 1 centralized critic
self.logger.debug(f"[_init_agent_state] flat_obs: {flat_obs.shape}")
feature_extractor_params = self.feature_extractor.init(feature_extractor_key, flat_obs)
# self.logger.debug(
# f"[_init_agent_state] feature_extractor_params: {
# jax.tree.map(lambda x: x.shape, feature_extractor_params)
# }"
# )
critic_input = self.feature_extractor.apply(feature_extractor_params, flat_obs)
self.logger.debug(f"[_init_agent_state] critic_input: {critic_input.shape}")
critic_params = self.critic.init(critic_key, critic_input)
# self.logger.debug(
# f"[_init_agent_state] critic_params: {jax.tree.map(lambda x: x.shape, critic_params)}"
# )
return TrainState.create(
apply_fn=None,
params=asdict(
AgentParams(
sensor_params,
actor_params,
critic_params,
feature_extractor_params,
message_passer_params,
)
),
tx=optax.chain(
optax.clip_by_global_norm(self.ppo.max_grad_norm),
optax.inject_hyperparams(optax.adam)(
learning_rate=partial(
_linear_schedule,
minibatch_count=self.ppo.num_minibatches,
update_epochs=self.ppo.update_epochs,
num_iterations=self.num_iterations,
learning_rate=self.ppo.learning_rate,
)
if self.ppo.anneal_lr
else self.ppo.learning_rate,
eps=1e-5,
),
),
)
def _init_episode_stats(self) -> EpisodeStatistics:
self.logger.info("[EPISODE STATS]: Initializing episode stats...")
return EpisodeStatistics(
episode_returns=jnp.zeros(self.ppo.num_envs, dtype=jnp.float32),
episode_lengths=jnp.zeros(self.ppo.num_envs, dtype=jnp.int32),
returned_episode_returns=jnp.zeros(self.ppo.num_envs, jnp.float32),
returned_episode_lengths=jnp.zeros(self.ppo.num_envs, dtype=jnp.int32),
)
def _update_obs_stats(self, obs: jnp.ndarray):
batch_mean = jnp.mean(obs, axis=0)
batch_var = jnp.var(obs, axis=0)
batch_count = obs.shape[0]
delta = batch_mean - self.obs_mean
total_count = self.obs_count + batch_count
new_mean = self.obs_mean + delta * batch_count / total_count
m_a = self.obs_var * self.obs_count
m_b = batch_var * batch_count
M2 = m_a + m_b + delta**2 * self.obs_count * batch_count / total_count
new_var = M2 / total_count
self.obs_mean = new_mean
self.obs_var = new_var
self.obs_count = total_count
def _rollout(self, env_state, next_obs, next_done) -> tuple[Any, ...]:
return self._rollout_jit(
self.agent_state,
self.episode_stats,
env_state,
next_obs,
next_done,
self.key,
)
def _compute_gae(self, storage, next_obs, next_done) -> Storage:
return self._compute_gae_jit(
self.agent_state,
storage,
next_obs,
next_done,
)
def _log(
self,
global_step,
episode_stats,
start_time,
iteration_time_start,
training_measurements,
storage,
):
data = jax.device_get(
{
"rewards": storage.rewards,
"values": storage.values,
"returns": storage.returns,
"advantages": storage.advantages,
}
)
rollout_metrics = {
"rollout/reward_mean": float(np.mean(data["rewards"])),
"rollout/return_mean": float(np.mean(data["returns"])),
"rollout/value_mean": float(np.mean(data["values"])),
"rollout/advantage_mean": float(np.mean(data["advantages"])),
"rollout/advantage_std": float(np.std(data["advantages"])),
"rollout/value_vs_return_mse": float(np.mean((data["values"] - data["returns"]) ** 2)),
}
metrics = {
"charts/episodic_return": training_measurements.avg_episodic_return,
"charts/episodic_length": float(
np.mean(jax.device_get(episode_stats.returned_episode_lengths))
),
"charts/explained_variance": training_measurements.explained_variance,
"losses/value_loss": training_measurements.v_loss[-1, -1].item(),
"losses/policy_loss": training_measurements.pg_loss[-1, -1].item(),
"losses/entropy": training_measurements.entropy_loss[-1, -1].item(),
"losses/approx_kl": training_measurements.approx_kl[-1, -1].item(),
"charts/learning_rate": self.agent_state.opt_state[1]
.hyperparams["learning_rate"]
.item(),
"charts/SPS": int(global_step / (time.time() - start_time)),
"charts/SPS_update": int(
self.ppo.num_envs * self.ppo.num_steps / (time.time() - iteration_time_start)
),
"termi_trunci/num_terminated": training_measurements.num_terminated,
"termi_trunci/num_truncated": training_measurements.num_truncated,
"termi_trunci/avg_terminated_ep_length": training_measurements.avg_terminated_length,
"termi_trunci/avg_truncated_ep_length": training_measurements.avg_truncated_length,
**rollout_metrics,
}
self.logger.log(metrics, step=global_step)
def _step(self, env_state, next_obs, next_done, iteration: int) -> tuple:
if iteration == 1:
self.logger.log_non_interactive(f"Starting first rollout (JIT): {time.ctime()}")
self.logger.info(f"[_step] next_obs (in): {next_obs.shape}")
(
self.agent_state,
self.episode_stats,
next_obs,
next_done,
storage,
self.key,
next_env_state,
) = self._rollout(env_state, next_obs, next_done)
self.logger.info(f"[_step] next_obs (post-rollout): {next_obs.shape}")
if iteration == 1:
self.logger.log_non_interactive(f"First rollout completed: {time.ctime()}")
storage = self._compute_gae(storage, next_obs, next_done)
self.logger.info(f"[_step] storage.obs (post-gae): {storage.obs.shape}")
if iteration == 1:
self.logger.log_non_interactive(f"Starting first PPO update (JIT): {time.ctime()}")
self.agent_state, loss, pg_loss, v_loss, entropy_loss, approx_kl, self.key = (
self._ppo.update_ppo(self.agent_state, storage, self.key)
)
if iteration == 1:
self.logger.log_non_interactive(f"First PPO update completed: {time.ctime()}")
avg_episodic_return = float(
jnp.mean(jax.device_get(self.episode_stats.returned_episode_returns)).item()
)
explained_var = _compute_explained_variance(storage.values, storage.returns)
terminated = next_env_state.terminated
truncated = next_env_state.truncated
episode_lengths = self.episode_stats.returned_episode_lengths
num_terminated = int(jnp.sum(terminated).item())
num_truncated = int(jnp.sum(truncated).item())
avg_terminated_length = jnp.sum(episode_lengths * terminated) / jnp.maximum(
jnp.sum(terminated), 1
)
avg_truncated_length = jnp.sum(episode_lengths * truncated) / jnp.maximum(
jnp.sum(truncated), 1
)
return (
next_env_state,
next_obs,
next_done,
TrainingMeasurements(
loss=loss,
pg_loss=pg_loss,
v_loss=v_loss,
entropy_loss=entropy_loss,
approx_kl=approx_kl,
avg_episodic_return=avg_episodic_return,
explained_variance=explained_var,
num_terminated=num_terminated,
num_truncated=num_truncated,
avg_terminated_length=avg_terminated_length,
avg_truncated_length=avg_truncated_length,
),
storage,
)
def _close(self):
self.env.close()
def _save_model(self, model_path: str):
self.logger.info("[SAVE]: Saving the final model...")
self.logger.save_final_model(params=self.agent_state.params, metadata=asdict(self.cfg))
def _save_checkpoint(self, iteration: int):
self.logger.info(f"[SAVE]: Saving checkpoint at iteration {iteration}...")
self.logger.save_checkpoint(
params=self.agent_state.params, step=iteration, metadata=asdict(self.cfg)
)
def train(self):
"""
Train the PPO agent for a specified number of iterations.
Closes the environment at the end of training.
"""
self.logger.info(f"running name: {self.run_name}")
self.logger.info("[TRAIN]: Resetting environment...")
self.logger.log_non_interactive(f"Initial reset started: {time.ctime()}")
env_state = self.env.reset(seed=self.experiment.seed)
next_obs = _convert_obs_dict_to_array_morphology(
env_state.observations,
self.morph_mode,
self.segments_per_arm,
)
self.logger.info(f"[train] next_obs: {next_obs.shape}")
next_done = jnp.zeros(self.ppo.num_envs, dtype=jnp.bool_)
self.logger.log_non_interactive(f"Initial reset completed: {time.ctime()}")
global_step = 0
start_time = time.time()
iter_bar = self.logger.progress_bar(range(1, self.num_iterations + 1))
for iteration in iter_bar:
iteration_time_start = time.time()
env_state, next_obs, next_done, training_measurements, storage = self._step(
env_state, next_obs, next_done, iteration=iteration
)
self.logger.info(f"[train] next_obs (post-step): {next_obs.shape}")
self._update_obs_stats(next_obs)
next_obs = _normalize_obs(next_obs, self.obs_mean, self.obs_var)
global_step += self.ppo.num_steps * self.ppo.num_envs
self._log(
global_step,
self.episode_stats,
start_time,
iteration_time_start,
training_measurements,
storage,
)
sps = int(global_step / (time.time() - start_time))
remaining_steps = self.ppo.total_timesteps - global_step
eta_seconds = int(remaining_steps / sps) if sps > 0 else 0
eta_str = str(datetime.timedelta(seconds=eta_seconds))
self.logger.log_non_interactive(
f"Iteration {iteration}/{self.num_iterations} | "
f"Step {global_step}/{self.ppo.total_timesteps} | "
f"SPS {sps} | "
f"Return {training_measurements.avg_episodic_return:.4f} | "
f"ETA {eta_str}"
)
if self.logging_cfg.save_checkpoints and self.logging_cfg.checkpoint_frequency > 0:
if iteration % self.logging_cfg.checkpoint_frequency == 0:
self._save_checkpoint(iteration)
if getattr(self.cfg.experiment, "debug_sanity", False):
self.logger.info("\n[SANITY CHECK] Successfully completed 1 epoch")
break
if self.logging_cfg.save_model:
model_path = f"{self.run_dir}/{self.experiment.exp_name}.cleanrl_model"
self._save_model(model_path=model_path)
self._close()