garage.np.exploration_policies.epsilon_greedy_policy

ϵ-greedy exploration strategy.

Random exploration according to the value of epsilon.

class EpsilonGreedyPolicy(env_spec, policy, *, total_timesteps, max_epsilon=1.0, min_epsilon=0.02, decay_ratio=0.1)[source]

Bases: garage.np.exploration_policies.exploration_policy.ExplorationPolicy

Inheritance diagram of garage.np.exploration_policies.epsilon_greedy_policy.EpsilonGreedyPolicy

ϵ-greedy exploration strategy.

Select action based on the value of ϵ. ϵ will decrease from max_epsilon to min_epsilon within decay_ratio * total_timesteps.

At state s, with probability 1 − ϵ: select action = argmax Q(s, a) ϵ : select a random action from an uniform distribution.

Parameters
  • env_spec (garage.envs.env_spec.EnvSpec) – Environment specification.

  • policy (garage.Policy) – Policy to wrap.

  • total_timesteps (int) – Total steps in the training, equivalent to max_episode_length * n_epochs.

  • max_epsilon (float) – The maximum(starting) value of epsilon.

  • min_epsilon (float) – The minimum(terminal) value of epsilon.

  • decay_ratio (float) – Fraction of total steps for epsilon decay.

get_action(self, observation)[source]

Get action from this policy for the input observation.

Parameters

observation (numpy.ndarray) – Observation from the environment.

Returns

An action with noise. dict: Arbitrary policy state information (agent_info).

Return type

np.ndarray

get_actions(self, observations)[source]

Get actions from this policy for the input observations.

Parameters

observations (numpy.ndarray) – Observation from the environment.

Returns

Actions with noise. List[dict]: Arbitrary policy state information (agent_info).

Return type

np.ndarray

update(self, episode_batch)[source]

Update the exploration policy using a batch of trajectories.

Parameters

episode_batch (EpisodeBatch) – A batch of trajectories which were sampled with this policy active.

get_param_values(self)[source]

Get parameter values.

Returns

Values of each parameter.

Return type

list or dict

set_param_values(self, params)[source]

Set param values.

Parameters

params (np.ndarray) – A numpy array of parameter values.

reset(self, dones=None)

Reset the state of the exploration.

Parameters

dones (List[bool] or numpy.ndarray or None) – Which vectorization states to reset.