Start PPO

This commit is contained in:
Antonin Raffin 2019-09-18 13:10:27 +02:00
parent 2a660e9a41
commit 54dd7ea60d
8 changed files with 403 additions and 50 deletions

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@ -6,6 +6,7 @@ import torch as th
import numpy as np
from torchy_baselines.common.policies import get_policy_from_name
from torchy_baselines.common.utils import set_random_seed
class BaseRLModel(object):
@ -182,8 +183,13 @@ class BaseRLModel(object):
"""
raise NotImplementedError()
def seed(self, seed=0):
set_random_seed(seed, using_cuda=self.device == th.device('cuda'))
if self.env is not None:
self.env.seed(seed)
def collect_rollouts(self, env, n_episodes=1, action_noise_std=0.0,
deterministic=False, callback=None,
deterministic=False, callback=None, remove_timelimits=True,
start_timesteps=0, num_timesteps=0, replay_buffer=None):
episode_rewards = []
@ -209,7 +215,7 @@ class BaseRLModel(object):
# Rescale and perform action
new_obs, reward, done, _ = env.step(self.max_action * action)
if hasattr(self.env, '_max_episode_steps'):
if hasattr(self.env, '_max_episode_steps') and remove_timelimits:
done_bool = 0 if episode_timesteps + 1 == env._max_episode_steps else float(done)
else:
done_bool = float(done)

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@ -0,0 +1,54 @@
import torch as th
from torch.distributions import Normal
class Distribution(object):
def __init__(self):
super(Distribution, self).__init__()
def log_prob(self, x):
"""
returns the log likelihood
:param x: (str) the labels of each index
:return: ([float]) The log likelihood of the distribution
"""
raise NotImplementedError
def kl_div(self, other):
"""
Calculates the Kullback-Leibler divergence from the given probabilty distribution
:param other: ([float]) the distibution to compare with
:return: (float) the KL divergence of the two distributions
"""
raise NotImplementedError
def entropy(self):
"""
Returns shannon's entropy of the probability
:return: (float) the entropy
"""
raise NotImplementedError
def sample(self):
"""
returns a sample from the probabilty distribution
:return: (Tensorflow Tensor) the stochastic action
"""
raise NotImplementedError
class DiagGaussianDistribution(object):
"""docstring for DiagGaussianDistribution."""
def __init__(self):
super(DiagGaussianDistribution, self).__init__()
self.distribution = None
def proba_distribution_from_latent(self, latent, init_scale=1.0, init_bias=0.0):
self.distribution = Normal()
def sample(self):
return self.distribution.rsample()

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@ -48,7 +48,46 @@ class BasePolicy(nn.Module):
:return: (np.ndarray)
"""
return th.nn.utils.parameters_to_vector(self.parameters())
return th.nn.utils.parameters_to_vector(self.parameters()).detach().cpu().numpy()
def create_mlp(input_dim, output_dim, net_arch,
activation_fn=nn.ReLU, squash_out=False):
modules = [nn.Linear(input_dim, net_arch[0]), activation_fn()]
for idx in range(len(net_arch) - 1):
modules.append(nn.Linear(net_arch[idx], net_arch[idx + 1]))
modules.append(activation_fn())
if output_dim > 0:
modules.append(nn.Linear(net_arch[-1], output_dim))
if squash_out:
modules.append(nn.Tanh())
return modules
class BaseNetwork(nn.Module):
"""docstring for BaseNetwork."""
def __init__(self):
super(BaseNetwork, self).__init__()
def load_from_vector(self, vector):
"""
Load parameters from a 1D vector.
:param vector: (np.ndarray)
"""
device = next(self.parameters()).device
th.nn.utils.vector_to_parameters(th.FloatTensor(vector).to(device), self.parameters())
def parameters_to_vector(self):
"""
Convert the parameters to a 1D vector.
:return: (np.ndarray)
"""
return th.nn.utils.parameters_to_vector(self.parameters()).detach().cpu().numpy()
_policy_registry = dict()

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@ -0,0 +1,107 @@
import torch as th
import torch.nn as nn
from torch.distributions import Normal
from torchy_baselines.common.policies import BasePolicy, register_policy, create_mlp, BaseNetwork
class Actor(BaseNetwork):
def __init__(self, state_dim, action_dim, net_arch=None, activation_fn=nn.ReLU):
super(Actor, self).__init__()
if net_arch is None:
net_arch = [64, 64]
# TODO: orthogonal initialization?
actor_net = create_mlp(state_dim, action_dim, net_arch, activation_fn, squash_out=True)
self.actor_net = nn.Sequential(*actor_net)
def forward(self, x):
return self.actor_net(x)
class Critic(BaseNetwork):
def __init__(self, state_dim, action_dim,
net_arch=None, activation_fn=nn.ReLU):
super(Critic, self).__init__()
if net_arch is None:
net_arch = [400, 300]
# TODO: solve pytorch parameter registration
# for _ in range(n_critics):
# q_net = create_mlp(state_dim + action_dim, 1, net_arch, activation_fn)
# self.q_net = nn.Sequential(*q_net)
# self.q_networks.append(self.q_net)
q1_net = create_mlp(state_dim + action_dim, 1, net_arch, activation_fn)
self.q1_net = nn.Sequential(*q1_net)
q2_net = create_mlp(state_dim + action_dim, 1, net_arch, activation_fn)
self.q2_net = nn.Sequential(*q2_net)
self.q_networks = [self.q1_net, self.q2_net]
def forward(self, obs, action):
qvalue_input = th.cat([obs, action], dim=1)
return [q_net(qvalue_input) for q_net in self.q_networks]
def q1_forward(self, obs, action):
return self.q_networks[0](th.cat([obs, action], dim=1))
class PPOPolicy(BasePolicy):
def __init__(self, observation_space, action_space,
learning_rate=1e-3, net_arch=None, device='cpu',
activation_fn=nn.Tanh):
super(PPOPolicy, self).__init__(observation_space, action_space, device)
self.state_dim = self.observation_space.shape[0]
self.action_dim = self.action_space.shape[0]
if net_arch is None:
net_arch = [64, 64]
self.net_arch = net_arch
self.activation_fn = activation_fn
self.net_args = {
'input_dim': self.state_dim,
'output_dim': -1,
'net_arch': self.net_arch,
'activation_fn': self.activation_fn
}
self.shared_net = None
self._build(learning_rate)
def _build(self, learning_rate):
shared_net = create_mlp(self.state_dim, output_dim=-1, self.net_arch, self.activation_fn)
self.shared_net = nn.Sequential(*shared_net).to(self.device)
self.actor_net = nn.Linear(self.net_arch[-1], self.action_dim)
self.value_net = nn.Linear(self.net_arch[-1], 1)
self.log_std = nn.Parameter(th.zeros(self.action_dim, 1))
self.optimizer = th.optim.Adam(self.parameters(), lr=learning_rate)
def forward(self, state):
latent = self.shared_net(state)
# TODO: initialize pi_mean weights properly
mean_actions = self.actor_net(latent)
action_distribution = Normal(mean_actions, self.log_std)
# Sample from the gaussian
action = action_distribution.rsample()
log_prob = action_distribution.log_prob()
# entropy = action_distribution.entropy()
value = self.value_net(latent)
return action, value, log_prob
def actor_forward(self):
latent = self.shared_net(state)
# TODO: initialize pi_mean weights properly
mean_actions = self.actor_net(latent)
action_distribution = Normal(mean_actions, self.log_std)
# Sample from the gaussian
action = action_distribution.rsample()
return action
def value_forward(self):
pass
MlpPolicy = PPOPolicy
register_policy("MlpPolicy", MlpPolicy)

190
torchy_baselines/ppo/ppo.py Normal file
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@ -0,0 +1,190 @@
import time
import torch as th
import torch.nn.functional as F
import numpy as np
from torchy_baselines.common.base_class import BaseRLModel
from torchy_baselines.common.utils import set_random_seed
from torchy_baselines.common.evaluation import evaluate_policy
from torchy_baselines.ppo.policies import ActorCriticPolicy
from torchy_baselines.common.replay_buffer import ReplayBuffer
class PPO(BaseRLModel):
"""
Implementation of Proximal Policy Optimization (PPO) (clip version)
Paper: https://arxiv.org/abs/1707.06347
Code: https://github.com/openai/spinningup/
"""
def __init__(self, policy, env, policy_kwargs=None, verbose=0,
learning_rate=1e-3, seed=0, device='auto',
n_optim=5, batch_size=100, n_steps=256,
gamma=0.99, lambda_=0.95,
_init_setup_model=True):
super(PPO, self).__init__(policy, env, ActorCriticPolicy, policy_kwargs, verbose, device)
self.max_action = np.abs(self.action_space.high)
self.learning_rate = learning_rate
self._seed = seed
self.batch_size = batch_size
self.n_optim = n_optim
self.n_steps = n_steps
self.gamma = gamma
self.lambda_ = lambda_
self.buffer_rollouts = None
if _init_setup_model:
self._setup_model()
def _setup_model(self):
state_dim, action_dim = self.observation_space.shape[0], self.action_space.shape[0]
self.seed(self._seed)
self.policy = self.policy(self.observation_space, self.action_space,
self.learning_rate, device=self.device, **self.policy_kwargs)
def select_action(self, observation):
# Normally not needed
observation = np.array(observation)
with th.no_grad():
observation = th.FloatTensor(observation.reshape(1, -1)).to(self.device)
return self.policy.actor_forward(observation).cpu().data.numpy().flatten()
def predict(self, observation, state=None, mask=None, deterministic=True):
"""
Get the model's action from an observation
:param observation: (np.ndarray) the input observation
:param state: (np.ndarray) The last states (can be None, used in recurrent policies)
:param mask: (np.ndarray) The last masks (can be None, used in recurrent policies)
:param deterministic: (bool) Whether or not to return deterministic actions.
:return: (np.ndarray, np.ndarray) the model's action and the next state (used in recurrent policies)
"""
return np.clip(self.select_action(observation), -self.max_action, self.max_action)
def train_actor(self, n_iterations=1, batch_size=100, tau_actor=0.005, tau_critic=0.005, replay_data=None):
for it in range(n_iterations):
# Sample replay buffer
if replay_data is None:
state, action, next_state, done, reward = self.replay_buffer.sample(batch_size)
else:
state, action, next_state, done, reward = replay_data
# Compute actor loss
actor_loss = -self.critic.q1_forward(state, self.actor(state)).mean()
# Optimize the actor
self.actor.optimizer.zero_grad()
actor_loss.backward()
self.actor.optimizer.step()
# Update the frozen target models
if tau_critic > 0:
for param, target_param in zip(self.critic.parameters(), self.critic_target.parameters()):
target_param.data.copy_(tau_critic * param.data + (1 - tau_critic) * target_param.data)
for param, target_param in zip(self.actor.parameters(), self.actor_target.parameters()):
target_param.data.copy_(tau_actor * param.data + (1 - tau_actor) * target_param.data)
def train(self, n_iterations, batch_size=100, discount=0.99,
tau=0.005, policy_noise=0.2, noise_clip=0.5, policy_freq=2):
for it in range(n_iterations):
# Sample replay buffer
replay_data = self.replay_buffer.sample(batch_size)
self.train_critic(replay_data=replay_data)
# Delayed policy updates
if it % policy_freq == 0:
self.train_actor(replay_data=replay_data)
def learn(self, total_timesteps, callback=None, log_interval=100,
eval_freq=-1, n_eval_episodes=5, tb_log_name="TD3", reset_num_timesteps=True):
timesteps_since_eval = 0
episode_num = 0
evaluations = []
start_time = time.time()
while self.num_timesteps < total_timesteps:
if callback is not None:
# Only stop training if return value is False, not when it is None.
if callback(locals(), globals()) is False:
break
episode_reward, episode_timesteps = self.collect_rollouts(self.env, n_episodes=1,
action_noise_std=self.action_noise_std,
deterministic=False, callback=None,
start_timesteps=self.start_timesteps,
num_timesteps=self.num_timesteps,
replay_buffer=self.buffer_rollouts)
episode_num += 1
self.num_timesteps += episode_timesteps
timesteps_since_eval += episode_timesteps
if self.num_timesteps > 0:
if self.verbose > 1:
print("Total T: {} Episode Num: {} Episode T: {} Reward: {}".format(
self.num_timesteps, episode_num, episode_timesteps, episode_reward))
self.train(episode_timesteps, batch_size=self.batch_size, policy_freq=self.policy_freq)
# Evaluate episode
if 0 < eval_freq <= timesteps_since_eval:
timesteps_since_eval %= eval_freq
mean_reward, _ = evaluate_policy(self, self.env, n_eval_episodes)
evaluations.append(mean_reward)
if self.verbose > 0:
print("Eval num_timesteps={}, mean_reward={:.2f}".format(self.num_timesteps, evaluations[-1]))
print("FPS: {:.2f}".format(self.num_timesteps / (time.time() - start_time)))
return self
def save(self, path):
if not path.endswith('.pth'):
path += '.pth'
th.save(self.policy.state_dict(), path)
def load(self, path, env=None, **_kwargs):
if not path.endswith('.pth'):
path += '.pth'
if env is not None:
pass
self.policy.load_state_dict(th.load(path))
class PPOBuffer(ReplayBuffer):
"""docstring for PPOBuffer."""
def __init__(self, buffer_size, state_dim, action_dim, device='cpu',
lambda=0.95):
super(PPOBuffer, self).__init__(buffer_size, state_dim, action_dim, device)
self.returns = th.zeros(self.buffer_size, 1)
self.values = th.zeros(self.buffer_size, 1)
self.log_probs = th.zeros(self.buffer_size, 1)
self.advantages = th.zeros(self.buffer_size, 1)
def compute_gae(self):
"""
From https://github.com/openai/spinningup/blob/master/spinup/algos/ppo/ppo.py
"""
path_slice = slice(self.path_start_idx, self.pos)
rews = np.append(self.rewards[path_slice], last_val)
vals = np.append(self.val_buf[path_slice], last_val)
# the next two lines implement GAE-Lambda advantage calculation
deltas = rews[:-1] + self.gamma * vals[1:] - vals[:-1]
self.advantages[path_slice] = core.discount_cumsum(deltas, self.gamma * self.lam)
# the next line computes rewards-to-go, to be targets for the value function
self.ret_buf[path_slice] = core.discount_cumsum(rews, self.gamma)[:-1]
self.path_start_idx = self.pos

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@ -1,45 +1,7 @@
import torch as th
import torch.nn as nn
from torchy_baselines.common.policies import BasePolicy, register_policy
def create_mlp(input_dim, output_dim, net_arch,
activation_fn=nn.ReLU, squash_out=False):
modules = [nn.Linear(input_dim, net_arch[0]), activation_fn()]
for idx in range(len(net_arch) - 1):
modules.append(nn.Linear(net_arch[idx], net_arch[idx + 1]))
modules.append(activation_fn())
modules.append(nn.Linear(net_arch[-1], output_dim))
if squash_out:
modules.append(nn.Tanh())
return modules
class BaseNetwork(nn.Module):
"""docstring for BaseNetwork."""
def __init__(self):
super(BaseNetwork, self).__init__()
def load_from_vector(self, vector):
"""
Load parameters from a 1D vector.
:param vector: (np.ndarray)
"""
device = next(self.parameters()).device
th.nn.utils.vector_to_parameters(th.FloatTensor(vector).to(device), self.parameters())
def parameters_to_vector(self):
"""
Convert the parameters to a 1D vector.
:return: (np.ndarray)
"""
return th.nn.utils.parameters_to_vector(self.parameters()).detach().cpu().numpy()
from torchy_baselines.common.policies import BasePolicy, register_policy, create_mlp, BaseNetwork
class Actor(BaseNetwork):

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@ -6,7 +6,6 @@ import numpy as np
from torchy_baselines.common.base_class import BaseRLModel
from torchy_baselines.common.replay_buffer import ReplayBuffer
from torchy_baselines.common.utils import set_random_seed
from torchy_baselines.common.evaluation import evaluate_policy
from torchy_baselines.td3.policies import TD3Policy
@ -31,20 +30,16 @@ class TD3(BaseRLModel):
self.learning_rate = learning_rate
self.buffer_size = buffer_size
self.start_timesteps = start_timesteps
self.seed = seed
self._seed = seed
self.policy_freq = policy_freq
self.batch_size = batch_size
if _init_setup_model:
self._setup_model()
def _setup_model(self, seed=None):
def _setup_model(self):
state_dim, action_dim = self.observation_space.shape[0], self.action_space.shape[0]
set_random_seed(self.seed, using_cuda=self.device == th.device('cuda'))
if self.env is not None:
self.env.seed(self.seed)
self.seed(self._seed)
self.replay_buffer = ReplayBuffer(self.buffer_size, state_dim, action_dim, self.device)
self.policy = self.policy(self.observation_space, self.action_space,
self.learning_rate, device=self.device, **self.policy_kwargs)