arlbench.core.algorithms.sac

class arlbench.core.algorithms.sac.SAC(hpo_config, env, eval_env=None, deterministic_eval=True, cnn_policy=False, nas_config=None, track_metrics=False, track_trajectories=False)

Bases: Algorithm

JAX-based implementation of Soft-Actor-Critic (SAC).

static get_checkpoint_factory(runner_state, train_result)

Creates a factory dictionary of all posssible checkpointing options for SAC.

Parameters:

• runner_state (SACRunnerState) – Algorithm runner state.

• train_result (SACTrainingResult | None) – Training result.

Returns:

Dictionary of factory functions containing:

• actor_opt_state

• critic_opt_state

• alpha_opt_state

• actor_network_params

• critic_network_params

• critic_target_params

• alpha_network_params

• actor_loss

• critic_loss

• alpha_loss

• trajectories

Return type:

dict[str, Callable]

static get_default_hpo_config()

Returns the default HPO configuration for SAC.

Return type:

Configuration

static get_default_nas_config()

Returns the default NAS configuration for SAC.

Return type:

Configuration

static get_hpo_config_space(seed=None)

Returns the hyperparameter configuration space for SAC.

Return type:

ConfigurationSpace

static get_nas_config_space(seed=None)

Returns the neural architecture search (NAS) configuration space for SAC.

Return type:

ConfigurationSpace

init(rng, buffer_state=None, actor_network_params=None, critic_network_params=None, critic_target_params=None, alpha_network_params=None, actor_opt_state=None, critic_opt_state=None, alpha_opt_state=None)

Initializes SAC state. Passed parameters are not initialized and included in the final state.

Parameters:

• actor_network_params (FrozenDict | dict | None, optional) – Actor network parameters. Defaults to None.

• critic_network_params (FrozenDict | dict | None, optional) – Critic network parameters. Defaults to None.

• critic_target_params (FrozenDict | dict | None, optional) – Critic target network parameters. Defaults to None.

• alpha_network_params (FrozenDict | dict | None, optional) – Alpha network parameters. Defaults to None.

• actor_opt_state (optax.OptState | None, optional) – Actor optimizer state. Defaults to None.

• critic_opt_state (optax.OptState | None, optional) – Critic optimizer state. Defaults to None.

• alpha_opt_state (optax.OptState | None, optional) – Alpha optimizer state. Defaults to None.

Returns:

SAC state.

Return type:

SACState

predict(runner_state, obs, rng, deterministic=True)

Predict action(s) based on the current observation(s).

Parameters:

• runner_state (SACRunnerState) – Algorithm runner state.

• obs (jnp.ndarray) – Observation(s).

• rng (chex.PRNGKey | None, optional) – Not used in DQN. Random generator key in other algorithmsDefaults to None.

• deterministic (bool) – Not used in DQN. Return deterministic action in other algorithm. Defaults to True.

Returns:

Action(s).

Return type:

jnp.ndarray

train(runner_state, buffer_state, n_total_timesteps=1000000, n_eval_steps=100, n_eval_episodes=10)

Performs one full training.

Parameters:

• runner_state (SACTrainReturnT) – SAC runner state.

• _ (None) – Unused parameter (buffer_state in other algorithms).

• n_total_timesteps (int, optional) – Total number of training timesteps. Update steps = n_total_timesteps // n_envs. Defaults to 1000000.

• n_eval_steps (int, optional) – Number of evaluation steps during training.

• n_eval_episodes (int, optional) – Number of evaluation episodes per evaluation during training.

Returns:

Tuple of PPO algorithm state and training result.

Return type:

SACTrainReturnT

update_actor(actor_train_state, critic_train_state, alpha_train_state, experience, is_weights, rng)

Updates the actor network parameters.

Parameters:

• actor_train_state (SACTrainState) – Actor train state.

• critic_train_state (SACTrainState) – Critic train state.

• alpha_train_state (SACTrainState) – Alpha train state.

• experience (TimeStep) – Experience (batch of TimeSteps).

• is_weights (jnp.ndarray) – Whether to use weights for PER or not.

• rng (chex.PRNGKey) – Random number generator key.

Returns:

_description_

Return type:

tuple[SACTrainState, jnp.ndarray, jnp.ndarray, FrozenDict, chex.PRNGKey]

update_alpha(alpha_train_state, entropy)

Update alpha network parameters.

Parameters:

• alpha_train_state (SACTrainState) – Alpha training state.

• entropy (jnp.ndarray) – Entropy values.

Returns:

Updated trainingi state and metrics.

Return type:

tuple[SACTrainState, jnp.ndarray]

update_critic(actor_train_state, critic_train_state, alpha_train_state, experience, is_weights, rng)

Updates the critic network parameters.

Parameters:

• actor_train_state (SACTrainState) – Actor train state.

• critic_train_state (SACTrainState) – Critic train state.

• alpha_train_state (SACTrainState) – Alpha train state.

• experience (Transition) – Experience (batch of transitions).

• rng (chex.PRNGKey) – Random number generator key.

Returns:

Updated training state and metrics.

Return type:

tuple[SACTrainState, jnp.ndarray, jnp.ndarray, FrozenDict, chex.PRNGKey]

class arlbench.core.algorithms.sac.SACMetrics(actor_loss: jnp.ndarray, critic_loss: jnp.ndarray, alpha_loss: jnp.ndarray, td_error: jnp.ndarray, actor_grads: FrozenDict, critic_grads: FrozenDict)

Bases: NamedTuple

SAC metrics returned by train function. Consists of (actor_loss, critic_loss, alpha_loss, td_error, actor_grads, critic_grads).

actor_grads: FrozenDict

Alias for field number 4

actor_loss: Array

Alias for field number 0

alpha_loss: Array

Alias for field number 2

critic_grads: FrozenDict

Alias for field number 5

critic_loss: Array

Alias for field number 1

td_error: Array

Alias for field number 3

class arlbench.core.algorithms.sac.SACRunnerState(rng: chex.PRNGKey, actor_train_state: SACTrainState, critic_train_state: SACTrainState, alpha_train_state: SACTrainState, normalizer_state: RunningStatisticsState, env_state: Any, obs: chex.Array, global_step: int)

Bases: NamedTuple

SAC runner state. Consists of (rng, actor_train_state, critic_train_state, alpha_train_state, env_state, obs, global_step).

actor_train_state: SACTrainState

Alias for field number 1

alpha_train_state: SACTrainState

Alias for field number 3

critic_train_state: SACTrainState

Alias for field number 2

env_state: Any

Alias for field number 5

global_step: int

Alias for field number 7

normalizer_state: RunningStatisticsState

Alias for field number 4

obs: Union[Array, ndarray, bool_, number]

Alias for field number 6

rng: Array

Alias for field number 0

class arlbench.core.algorithms.sac.SACState(runner_state: SACRunnerState, buffer_state: PrioritisedTrajectoryBufferState)

Bases: NamedTuple

SAC algorithm state. Consists of (runner_state, buffer_state).

buffer_state: PrioritisedTrajectoryBufferState

Alias for field number 1

runner_state: SACRunnerState

Alias for field number 0

arlbench.core.algorithms.sac.SACTrainReturnT

alias of tuple[SACState, SACTrainingResult]

class arlbench.core.algorithms.sac.SACTrainingResult(eval_rewards: jnp.ndarray, trajectories: Transition | None, metrics: SACMetrics | None)

Bases: NamedTuple

SAC training result. Consists of (eval_rewards, trajectories, metrics).

eval_rewards: Array

Alias for field number 0

metrics: SACMetrics | None

Alias for field number 2

trajectories: Transition | None

Alias for field number 1

Modules

models	SAC models for the actor and critic networks.
sac	SAC algorithm.

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