def objective(self, x):
model = GMM()
model.copy_model(self.initial_model)
model.update_gaussians(np.asarray(x))
accuracy, mean_return, mean_length = model.evaluate(self.env,
max_steps=600,
num_episodes=1)
print("Accuracy:", accuracy, "mean_return:", mean_return)
return -mean_return
class SAC_GMM_Agent(SAC_Agent):
def __init__(self, model, window_size=32, *args, **kwargs):
self.initial_model = model # Initial model provided
self.model = GMM()
self.model.copy_model(self.initial_model) # Model used for training
self.window_size = window_size
self.burn_in_steps = 1000
super(SAC_GMM_Agent, self).__init__(*args, **kwargs)
def get_action_space(self):
if not hasattr(self, 'action_space'):
priors_high = np.ones(self.model.priors.size)
mu_high = np.ones(self.model.mu.size)
action_high = np.concatenate((priors_high, mu_high), axis=-1)
action_low = -action_high
self.action_space = gym.spaces.Box(action_low, action_high)
return self.action_space
def update_gaussians(self, gmm_change):
# change of priors range: [-0.1, 0.1]
priors = gmm_change[:self.model.priors.size]
priors = priors.reshape(self.model.priors.shape) * 0.1
# change of mus range: [-0.01, 0.01]
mu = gmm_change[self.model.priors.size:]
mu = mu.reshape(self.model.mu.shape) * 0.01
change_dict = {"mu": mu, "prior": priors}
self.model.update_gaussians(change_dict)
def evaluate(self, num_episodes=5, render=False):
succesful_episodes, episodes_returns, episodes_lengths = 0, [], []
for episode in range(1, num_episodes + 1):
observation = self.env.reset()
episode_return, episode_length, left_steps = 0, 0, self.env.max_episode_steps
while left_steps > 0:
self.model.copy_model(self.initial_model)
gmm_change = self.get_action_from_observation(
observation, deterministic=True)
self.update_gaussians(gmm_change)
model_reward = 0
for step in range(self.window_size):
vel = self.model.predict_velocity_from_observation(
observation)
observation, reward, done, info = self.env.step(vel)
model_reward += reward
episode_length += 1
left_steps -= 1
if render:
self.env.render()
if done or left_steps <= 0:
break
episode_return += model_reward
if done:
break
if render:
self.env.render()
if ("success" in info) and info['success']:
succesful_episodes += 1
episodes_returns.append(episode_return)
episodes_lengths.append(episode_length)
accuracy = succesful_episodes / num_episodes
return accuracy, np.mean(episodes_returns), np.mean(episodes_lengths)
def train_episode(self, episode, exploration_episodes, log, render):
sac_steps = 0
episode_return, episode_length, left_steps = 0, 0, self.env.max_episode_steps
ep_critic_loss, ep_actor_loss, ep_alpha_loss = 0, 0, 0
observation = self.env.reset()
while left_steps > 0:
self.model.copy_model(self.initial_model)
if self.training_step < self.burn_in_steps:
gmm_change = np.zeros(self.action_space.shape)
else:
gmm_change = self.get_action_from_observation(
observation, deterministic=False)
self.update_gaussians(gmm_change)
model_reward = 0
curr_observation = observation
for step in range(self.window_size):
vel = self.model.predict_velocity_from_observation(
curr_observation)
curr_observation, reward, done, info = self.env.step(vel)
model_reward += reward
episode_length += 1
left_steps -= 1
if render:
self.env.render()
if done or left_steps <= 0:
break
critic_loss, actor_loss, alpha_loss = self.update(
observation, gmm_change, curr_observation, model_reward, done,
log)
observation = curr_observation
episode_return += model_reward
ep_critic_loss += critic_loss
ep_actor_loss += actor_loss
ep_alpha_loss += alpha_loss
self.training_step += 1 # SAC_Steps in total
sac_steps += 1 # SAC_Steps in this episode
if render:
self.env.render()
if done:
break
if log:
self.log_scalar('Train/Episode/critic_loss',
ep_critic_loss / sac_steps, episode)
self.log_scalar('Train/Episode/actor_loss',
ep_actor_loss / sac_steps, episode)
self.log_scalar('Train/Episode/alpha_loss',
ep_alpha_loss / sac_steps, episode)
self.log_episode_information(episode_return, episode_length,
episode, "Train")
return episode_return, episode_length