Fix for issue #128 - circular DQN import (#130)

rl_coach/agents/dqn_agent.py

@@ -36,6 +36,7 @@ class DQNAlgorithmParameters(AlgorithmParameters):
         self.num_steps_between_copying_online_weights_to_target = EnvironmentSteps(10000)
         self.num_consecutive_playing_steps = EnvironmentSteps(4)
         self.discount = 0.99
+        self.supports_parameter_noise = True
 
 
 class DQNNetworkParameters(NetworkParameters):

rl_coach/base_parameters.py

@@ -211,6 +211,9 @@ class AlgorithmParameters(Parameters):
         # Should the workers wait for full episode
         self.act_for_full_episodes = False
 
+        # Support for parameter noise
+        self.supports_parameter_noise = False
+
 
 class PresetValidationParameters(Parameters):
     def __init__(self,

rl_coach/exploration_policies/parameter_noise.py

@@ -18,7 +18,6 @@ from typing import List, Dict
 
 import numpy as np
 
-from rl_coach.agents.dqn_agent import DQNAgentParameters
 from rl_coach.architectures.layers import NoisyNetDense
 from rl_coach.base_parameters import AgentParameters, NetworkParameters
 from rl_coach.spaces import ActionSpace, BoxActionSpace, DiscreteActionSpace
@@ -30,7 +29,8 @@ from rl_coach.exploration_policies.exploration_policy import ExplorationPolicy,
 class ParameterNoiseParameters(ExplorationParameters):
     def __init__(self, agent_params: AgentParameters):
         super().__init__()
-        if not isinstance(agent_params, DQNAgentParameters):
+
+        if not agent_params.algorithm.supports_parameter_noise:
             raise ValueError("Currently only DQN variants are supported for using an exploration type of "
                              "ParameterNoise.")
 

rl_coach/filters/observation/observation_normalization_filter.py

@@ -87,3 +87,4 @@ class ObservationNormalizationFilter(ObservationFilter):
 
     def restore_state_from_checkpoint(self, checkpoint_dir: str, checkpoint_prefix: str):
         self.running_observation_stats.restore_state_from_checkpoint(checkpoint_dir, checkpoint_prefix)
+