garage.sampler.vec_worker
¶
Worker that “vectorizes” environments.
-
class
VecWorker
(*, seed, max_episode_length, worker_number, n_envs=DEFAULT_N_ENVS)¶ Bases:
garage.sampler.default_worker.DefaultWorker
Worker with a single policy and multiple environments.
Alternates between taking a single step in all environments and asking the policy for an action for every environment. This allows computing a batch of actions, which is generally much more efficient than computing a single action when using neural networks.
- Parameters
seed (int) – The seed to use to intialize random number generators.
max_episode_length (int or float) – The maximum length of episodes which will be sampled. Can be (floating point) infinity.
worker_number (int) – The number of the worker this update is occurring in. This argument is used set a different seed for each worker.
n_envs (int) – Number of environment copies to use.
-
DEFAULT_N_ENVS
= 8¶
-
update_agent
(self, agent_update)¶ Update an agent, assuming it implements
Policy
.- Parameters
agent_update (np.ndarray or dict or Policy) – If a tuple, dict, or np.ndarray, these should be parameters to agent, which should have been generated by calling Policy.get_param_values. Alternatively, a policy itself. Note that other implementations of Worker may take different types for this parameter.
-
update_env
(self, env_update)¶ Update the environments.
If passed a list (inside this list passed to the Sampler itself), distributes the environments across the “vectorization” dimension.
- Parameters
env_update (Environment or EnvUpdate or None) – The environment to replace the existing env with. Note that other implementations of Worker may take different types for this parameter.
- Raises
TypeError – If env_update is not one of the documented types.
ValueError – If the wrong number of updates is passed.
-
start_episode
(self)¶ Begin a new episode.
-
step_episode
(self)¶ Take a single time-step in the current episode.
- Returns
True iff at least one of the episodes was completed.
- Return type
-
collect_episode
(self)¶ Collect all completed episodes.
- Returns
- A batch of the episodes completed since the last call
to collect_episode().
- Return type
-
shutdown
(self)¶ Close the worker’s environments.
-
worker_init
(self)¶ Initialize a worker.
-
rollout
(self)¶ Sample a single episode of the agent in the environment.
- Returns
The collected episode.
- Return type