garage.replay_buffer.her_replay_buffer
¶
This module implements a Hindsight Experience Replay (HER).
See: https://arxiv.org/abs/1707.01495.
- class HERReplayBuffer(replay_k, reward_fn, capacity_in_transitions, env_spec)¶
Bases:
garage.replay_buffer.path_buffer.PathBuffer
Replay buffer for HER (Hindsight Experience Replay).
It constructs hindsight examples using future strategy.
- Parameters
replay_k (int) – Number of HER transitions to add for each regular Transition. Setting this to 0 means that no HER replays will be added.
reward_fn (callable) – Function to re-compute the reward with substituted goals.
capacity_in_transitions (int) – total size of transitions in the buffer.
env_spec (EnvSpec) – Environment specification.
- property n_transitions_stored¶
Return the size of the replay buffer.
- Returns
Size of the current replay buffer.
- Return type
- add_path(path)¶
Adds a path to the replay buffer.
For each transition in the given path except the last one, replay_k HER transitions will added to the buffer in addition to the one in the path. The last transition is added without sampling additional HER goals.
- add_episode_batch(episodes)¶
Add a EpisodeBatch to the buffer.
- Parameters
episodes (EpisodeBatch) – Episodes to add.
- sample_path()¶
Sample a single path from the buffer.
- Returns
A dict of arrays of shape (path_len, flat_dim).
- Return type
path
- sample_transitions(batch_size)¶
Sample a batch of transitions from the buffer.
- sample_timesteps(batch_size)¶
Sample a batch of timesteps from the buffer.
- Parameters
batch_size (int) – Number of timesteps to sample.
- Returns
The batch of timesteps.
- Return type
- clear()¶
Clear buffer.