garage.sampler.local_sampler¶
Sampler that runs workers in the main process.
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class
LocalSampler(worker_factory, agents, envs)[source]¶ Bases:
garage.sampler.sampler.Sampler
Sampler that runs workers in the main process.
This is probably the simplest possible sampler. It’s called the “Local” sampler because it runs everything in the same process and thread as where it was called from.
- Parameters
worker_factory (WorkerFactory) – Pickleable factory for creating workers. Should be transmitted to other processes / nodes where work needs to be done, then workers should be constructed there.
agents (Policy or List[Policy]) – Agent(s) to use to sample episodes. If a list is passed in, it must have length exactly worker_factory.n_workers, and will be spread across the workers.
envs (Environment or List[Environment]) – Environment from which episodes are sampled. If a list is passed in, it must have length exactly worker_factory.n_workers, and will be spread across the workers.
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classmethod
from_worker_factory(cls, worker_factory, agents, envs)[source]¶ Construct this sampler.
- Parameters
worker_factory (WorkerFactory) – Pickleable factory for creating workers. Should be transmitted to other processes / nodes where work needs to be done, then workers should be constructed there.
agents (Agent or List[Agent]) – Agent(s) to use to sample episodes. If a list is passed in, it must have length exactly worker_factory.n_workers, and will be spread across the workers.
envs (Environment or List[Environment]) – Environment from which episodes are sampled. If a list is passed in, it must have length exactly worker_factory.n_workers, and will be spread across the workers.
- Returns
An instance of cls.
- Return type
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obtain_samples(self, itr, num_samples, agent_update, env_update=None)[source]¶ Collect at least a given number transitions (timesteps).
- Parameters
itr (int) – The current iteration number. Using this argument is deprecated.
num_samples (int) – Minimum number of transitions / timesteps to sample.
agent_update (object) – Value which will be passed into the agent_update_fn before sampling episodes. If a list is passed in, it must have length exactly factory.n_workers, and will be spread across the workers.
env_update (object) – Value which will be passed into the env_update_fn before sampling episodes. If a list is passed in, it must have length exactly factory.n_workers, and will be spread across the workers.
- Returns
The batch of collected episodes.
- Return type
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obtain_exact_episodes(self, n_eps_per_worker, agent_update, env_update=None)[source]¶ Sample an exact number of episodes per worker.
- Parameters
n_eps_per_worker (int) – Exact number of episodes to gather for each worker.
agent_update (object) – Value which will be passed into the agent_update_fn before sampling episodes. If a list is passed in, it must have length exactly factory.n_workers, and will be spread across the workers.
env_update (object) – Value which will be passed into the env_update_fn before samplin episodes. If a list is passed in, it must have length exactly factory.n_workers, and will be spread across the workers.
- Returns
- Batch of gathered episodes. Always in worker
order. In other words, first all episodes from worker 0, then all episodes from worker 1, etc.
- Return type
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start_worker(self)¶ Initialize the sampler.
i.e. launching parallel workers if necessary.
This method is deprecated, please launch workers in construct instead.