ray/rllib/utils/exploration/tests/test_parameter_noise.py
Balaji Veeramani 7f1bacc7dc
[CI] Format Python code with Black (#21975)
See #21316 and #21311 for the motivation behind these changes.
2022-01-29 18:41:57 -08:00

232 lines
9.6 KiB
Python

import numpy as np
import unittest
import ray
import ray.rllib.agents.ddpg as ddpg
import ray.rllib.agents.dqn as dqn
from ray.rllib.utils.test_utils import check, framework_iterator
class TestParameterNoise(unittest.TestCase):
@classmethod
def setUpClass(cls) -> None:
ray.init(num_cpus=4)
@classmethod
def tearDownClass(cls) -> None:
ray.shutdown()
def test_ddpg_parameter_noise(self):
self.do_test_parameter_noise_exploration(
ddpg.DDPGTrainer,
ddpg.DEFAULT_CONFIG,
"Pendulum-v1",
{},
np.array([1.0, 0.0, -1.0]),
)
def test_dqn_parameter_noise(self):
self.do_test_parameter_noise_exploration(
dqn.DQNTrainer,
dqn.DEFAULT_CONFIG,
"FrozenLake-v1",
{"is_slippery": False, "map_name": "4x4"},
np.array(0),
)
def do_test_parameter_noise_exploration(
self, trainer_cls, config, env, env_config, obs
):
"""Tests, whether an Agent works with ParameterNoise."""
core_config = config.copy()
core_config["num_workers"] = 0 # Run locally.
core_config["env_config"] = env_config
for fw in framework_iterator(core_config):
config = core_config.copy()
# Algo with ParameterNoise exploration (config["explore"]=True).
# ----
config["exploration_config"] = {"type": "ParameterNoise"}
config["explore"] = True
trainer = trainer_cls(config=config, env=env)
policy = trainer.get_policy()
pol_sess = policy.get_session()
# Remove noise that has been added during policy initialization
# (exploration.postprocess_trajectory does add noise to measure
# the delta).
policy.exploration._remove_noise(tf_sess=pol_sess)
self.assertFalse(policy.exploration.weights_are_currently_noisy)
noise_before = self._get_current_noise(policy, fw)
check(noise_before, 0.0)
initial_weights = self._get_current_weight(policy, fw)
# Pseudo-start an episode and compare the weights before and after.
policy.exploration.on_episode_start(policy, tf_sess=pol_sess)
self.assertFalse(policy.exploration.weights_are_currently_noisy)
noise_after_ep_start = self._get_current_noise(policy, fw)
weights_after_ep_start = self._get_current_weight(policy, fw)
# Should be the same, as we don't do anything at the beginning of
# the episode, only one step later.
check(noise_after_ep_start, noise_before)
check(initial_weights, weights_after_ep_start)
# Setting explore=False should always return the same action.
a_ = trainer.compute_single_action(obs, explore=False)
self.assertFalse(policy.exploration.weights_are_currently_noisy)
noise = self._get_current_noise(policy, fw)
# We sampled the first noise (not zero anymore).
check(noise, 0.0, false=True)
# But still not applied b/c explore=False.
check(self._get_current_weight(policy, fw), initial_weights)
for _ in range(10):
a = trainer.compute_single_action(obs, explore=False)
check(a, a_)
# Noise never gets applied.
check(self._get_current_weight(policy, fw), initial_weights)
self.assertFalse(policy.exploration.weights_are_currently_noisy)
# Explore=None (default: True) should return different actions.
# However, this is only due to the underlying epsilon-greedy
# exploration.
actions = []
current_weight = None
for _ in range(10):
actions.append(trainer.compute_single_action(obs))
self.assertTrue(policy.exploration.weights_are_currently_noisy)
# Now, noise actually got applied (explore=True).
current_weight = self._get_current_weight(policy, fw)
check(current_weight, initial_weights, false=True)
check(current_weight, initial_weights + noise)
check(np.std(actions), 0.0, false=True)
# Pseudo-end the episode and compare weights again.
# Make sure they are the original ones.
policy.exploration.on_episode_end(policy, tf_sess=pol_sess)
weights_after_ep_end = self._get_current_weight(policy, fw)
check(current_weight - noise, weights_after_ep_end, decimals=5)
trainer.stop()
# DQN with ParameterNoise exploration (config["explore"]=False).
# ----
config = core_config.copy()
config["exploration_config"] = {"type": "ParameterNoise"}
config["explore"] = False
trainer = trainer_cls(config=config, env=env)
policy = trainer.get_policy()
pol_sess = policy.get_session()
# Remove noise that has been added during policy initialization
# (exploration.postprocess_trajectory does add noise to measure
# the delta).
policy.exploration._remove_noise(tf_sess=pol_sess)
self.assertFalse(policy.exploration.weights_are_currently_noisy)
initial_weights = self._get_current_weight(policy, fw)
# Noise before anything (should be 0.0, no episode started yet).
noise = self._get_current_noise(policy, fw)
check(noise, 0.0)
# Pseudo-start an episode and compare the weights before and after
# (they should be the same).
policy.exploration.on_episode_start(policy, tf_sess=pol_sess)
self.assertFalse(policy.exploration.weights_are_currently_noisy)
# Should be the same, as we don't do anything at the beginning of
# the episode, only one step later.
noise = self._get_current_noise(policy, fw)
check(noise, 0.0)
noisy_weights = self._get_current_weight(policy, fw)
check(initial_weights, noisy_weights)
# Setting explore=False or None should always return the same
# action.
a_ = trainer.compute_single_action(obs, explore=False)
# Now we have re-sampled.
noise = self._get_current_noise(policy, fw)
check(noise, 0.0, false=True)
for _ in range(5):
a = trainer.compute_single_action(obs, explore=None)
check(a, a_)
a = trainer.compute_single_action(obs, explore=False)
check(a, a_)
# Pseudo-end the episode and compare weights again.
# Make sure they are the original ones (no noise permanently
# applied throughout the episode).
policy.exploration.on_episode_end(policy, tf_sess=pol_sess)
weights_after_episode_end = self._get_current_weight(policy, fw)
check(initial_weights, weights_after_episode_end)
# Noise should still be the same (re-sampling only happens at
# beginning of episode).
noise_after = self._get_current_noise(policy, fw)
check(noise, noise_after)
trainer.stop()
# Switch off underlying exploration entirely.
# ----
config = core_config.copy()
if trainer_cls is dqn.DQNTrainer:
sub_config = {
"type": "EpsilonGreedy",
"initial_epsilon": 0.0, # <- no randomness whatsoever
"final_epsilon": 0.0,
}
else:
sub_config = {
"type": "OrnsteinUhlenbeckNoise",
"initial_scale": 0.0, # <- no randomness whatsoever
"final_scale": 0.0,
"random_timesteps": 0,
}
config["exploration_config"] = {
"type": "ParameterNoise",
"sub_exploration": sub_config,
}
config["explore"] = True
trainer = trainer_cls(config=config, env=env)
# Now, when we act - even with explore=True - we would expect
# the same action for the same input (parameter noise is
# deterministic).
policy = trainer.get_policy()
policy.exploration.on_episode_start(policy, tf_sess=pol_sess)
a_ = trainer.compute_single_action(obs)
for _ in range(10):
a = trainer.compute_single_action(obs, explore=True)
check(a, a_)
trainer.stop()
def _get_current_noise(self, policy, fw):
# If noise not even created yet, return 0.0.
if policy.exploration.noise is None:
return 0.0
noise = policy.exploration.noise[0][0][0]
if fw == "tf":
noise = policy.get_session().run(noise)
elif fw == "torch":
noise = noise.detach().cpu().numpy()
else:
noise = noise.numpy()
return noise
def _get_current_weight(self, policy, fw):
weights = policy.get_weights()
if fw == "torch":
# DQN model.
if "_hidden_layers.0._model.0.weight" in weights:
return weights["_hidden_layers.0._model.0.weight"][0][0]
# DDPG model.
else:
return weights["policy_model.action_0._model.0.weight"][0][0]
key = 0 if fw in ["tf2", "tfe"] else list(weights.keys())[0]
return weights[key][0][0]
if __name__ == "__main__":
import pytest
import sys
sys.exit(pytest.main(["-v", __file__]))