ray/rllib/agents/mbmpo/mbmpo_torch_policy.py

123 lines
4.9 KiB
Python

import gym
from gym.spaces import Box, Discrete
import logging
from typing import Tuple, Type
import ray
from ray.rllib.agents.a3c.a3c_torch_policy import vf_preds_fetches
from ray.rllib.agents.maml.maml_torch_policy import setup_mixins, \
maml_loss, maml_stats, maml_optimizer_fn, KLCoeffMixin
from ray.rllib.agents.ppo.ppo_tf_policy import setup_config
from ray.rllib.evaluation.postprocessing import compute_gae_for_sample_batch
from ray.rllib.models.catalog import ModelCatalog
from ray.rllib.models.modelv2 import ModelV2
from ray.rllib.models.torch.torch_action_dist import TorchDistributionWrapper
from ray.rllib.policy.policy import Policy
from ray.rllib.policy.policy_template import build_policy_class
from ray.rllib.utils.error import UnsupportedSpaceException
from ray.rllib.utils.framework import try_import_torch
from ray.rllib.utils.torch_utils import apply_grad_clipping
from ray.rllib.utils.typing import TrainerConfigDict
torch, nn = try_import_torch()
logger = logging.getLogger(__name__)
def validate_spaces(policy: Policy, observation_space: gym.spaces.Space,
action_space: gym.spaces.Space,
config: TrainerConfigDict) -> None:
"""Validates the observation- and action spaces used for the Policy.
Args:
policy (Policy): The policy, whose spaces are being validated.
observation_space (gym.spaces.Space): The observation space to
validate.
action_space (gym.spaces.Space): The action space to validate.
config (TrainerConfigDict): The Policy's config dict.
Raises:
UnsupportedSpaceException: If one of the spaces is not supported.
"""
# Only support single Box or single Discrete spaces.
if not isinstance(action_space, (Box, Discrete)):
raise UnsupportedSpaceException(
"Action space ({}) of {} is not supported for "
"MB-MPO. Must be [Box|Discrete].".format(action_space, policy))
# If Box, make sure it's a 1D vector space.
elif isinstance(action_space, Box) and len(action_space.shape) > 1:
raise UnsupportedSpaceException(
"Action space ({}) of {} has multiple dimensions "
"{}. ".format(action_space, policy, action_space.shape) +
"Consider reshaping this into a single dimension Box space "
"or using the multi-agent API.")
def make_model_and_action_dist(
policy: Policy,
obs_space: gym.spaces.Space,
action_space: gym.spaces.Space,
config: TrainerConfigDict) -> \
Tuple[ModelV2, Type[TorchDistributionWrapper]]:
"""Constructs the necessary ModelV2 and action dist class for the Policy.
Args:
policy (Policy): The TFPolicy that will use the models.
obs_space (gym.spaces.Space): The observation space.
action_space (gym.spaces.Space): The action space.
config (TrainerConfigDict): The SAC trainer's config dict.
Returns:
ModelV2: The ModelV2 to be used by the Policy. Note: An additional
target model will be created in this function and assigned to
`policy.target_model`.
"""
# Get the output distribution class for predicting rewards and next-obs.
policy.distr_cls_next_obs, num_outputs = ModelCatalog.get_action_dist(
obs_space, config, dist_type="deterministic", framework="torch")
# Build one dynamics model if we are a Worker.
# If we are the main MAML learner, build n (num_workers) dynamics Models
# for being able to create checkpoints for the current state of training.
device = (torch.device("cuda")
if torch.cuda.is_available() else torch.device("cpu"))
policy.dynamics_model = ModelCatalog.get_model_v2(
obs_space,
action_space,
num_outputs=num_outputs,
model_config=config["dynamics_model"],
framework="torch",
name="dynamics_ensemble",
).to(device)
action_dist, num_outputs = ModelCatalog.get_action_dist(
action_space, config, framework="torch")
# Create the pi-model and register it with the Policy.
policy.pi = ModelCatalog.get_model_v2(
obs_space,
action_space,
num_outputs=num_outputs,
model_config=config["model"],
framework="torch",
name="policy_model",
)
return policy.pi, action_dist
# Build a child class of `TorchPolicy`, given the custom functions defined
# above.
MBMPOTorchPolicy = build_policy_class(
name="MBMPOTorchPolicy",
framework="torch",
get_default_config=lambda: ray.rllib.agents.mbmpo.mbmpo.DEFAULT_CONFIG,
make_model_and_action_dist=make_model_and_action_dist,
loss_fn=maml_loss,
stats_fn=maml_stats,
optimizer_fn=maml_optimizer_fn,
extra_action_out_fn=vf_preds_fetches,
postprocess_fn=compute_gae_for_sample_batch,
extra_grad_process_fn=apply_grad_clipping,
before_init=setup_config,
after_init=setup_mixins,
mixins=[KLCoeffMixin])