def get_dataset_stats(self, data):
torch_input = ptu.from_numpy(normalize_image(data))
mus, log_vars = self.model.encode(torch_input)
mus = ptu.get_numpy(mus)
mean = np.mean(mus, axis=0)
std = np.std(mus, axis=0)
return mus, mean, std
def _reconstruct_img(self, flat_img):
latent_distribution_params = self.vae.encode(
ptu.from_numpy(flat_img.reshape(1, -1)))
reconstructions, _ = self.vae.decode(latent_distribution_params[0])
imgs = ptu.get_numpy(reconstructions)
imgs = imgs.reshape(1, self.input_channels, self.imsize, self.imsize)
return imgs[0]
def train_from_torch(self, batch):
rewards = batch['rewards'] * self.reward_scale
terminals = batch['terminals']
obs = batch['observations']
actions = batch['actions']
next_obs = batch['next_observations']
"""
Compute loss
"""
target_q_values = self.target_qf(next_obs).detach().max(
1, keepdim=True
)[0]
y_target = rewards + (1. - terminals) * self.discount * target_q_values
y_target = y_target.detach()
# actions is a one-hot vector
y_pred = torch.sum(self.qf(obs) * actions, dim=1, keepdim=True)
qf_loss = self.qf_criterion(y_pred, y_target)
"""
Soft target network updates
"""
self.qf_optimizer.zero_grad()
qf_loss.backward()
self.qf_optimizer.step()
"""
Soft Updates
"""
if self._n_train_steps_total % self.target_update_period == 0:
ptu.soft_update_from_to(
self.qf, self.target_qf, self.soft_target_tau
)
"""
Save some statistics for eval using just one batch.
"""
if self._need_to_update_eval_statistics:
self._need_to_update_eval_statistics = False
self.eval_statistics['QF Loss'] = np.mean(ptu.get_numpy(qf_loss))
self.eval_statistics.update(create_stats_ordered_dict(
'Y Predictions',
ptu.get_numpy(y_pred),
))
def _update_info(self, info, obs):
latent_distribution_params = self.vae.encode(
ptu.from_numpy(obs[self.vae_input_observation_key].reshape(1, -1)))
latent_obs, logvar = ptu.get_numpy(
latent_distribution_params[0])[0], ptu.get_numpy(
latent_distribution_params[1])[0]
# assert (latent_obs == obs['latent_observation']).all()
latent_goal = self.desired_goal['latent_desired_goal']
dist = latent_goal - latent_obs
var = np.exp(logvar.flatten())
var = np.maximum(var, self.reward_min_variance)
err = dist * dist / 2 / var
mdist = np.sum(err) # mahalanobis distance
info["vae_mdist"] = mdist
info["vae_success"] = 1 if mdist < self.epsilon else 0
info["vae_dist"] = np.linalg.norm(dist, ord=self.norm_order)
info["vae_dist_l1"] = np.linalg.norm(dist, ord=1)
info["vae_dist_l2"] = np.linalg.norm(dist, ord=2)
def train_epoch(self,
epoch,
sample_batch=None,
batches=100,
from_rl=False):
self.model.train()
losses = []
log_probs = []
kles = []
zs = []
beta = float(self.beta_schedule.get_value(epoch))
for batch_idx in range(batches):
if sample_batch is not None:
data = sample_batch(self.batch_size, epoch)
# obs = data['obs']
next_obs = data['next_obs']
# actions = data['actions']
else:
next_obs = self.get_batch(epoch=epoch)
obs = None
actions = None
self.optimizer.zero_grad()
reconstructions, obs_distribution_params, latent_distribution_params = self.model(
next_obs)
log_prob = self.model.logprob(next_obs, obs_distribution_params)
kle = self.model.kl_divergence(latent_distribution_params)
encoder_mean = self.model.get_encoding_from_latent_distribution_params(
latent_distribution_params)
z_data = ptu.get_numpy(encoder_mean.cpu())
for i in range(len(z_data)):
zs.append(z_data[i, :])
loss = -1 * log_prob + beta * kle
self.optimizer.zero_grad()
loss.backward()
losses.append(loss.item())
log_probs.append(log_prob.item())
kles.append(kle.item())
self.optimizer.step()
if self.log_interval and batch_idx % self.log_interval == 0:
print('Train Epoch: {} [{}/{} ({:.0f}%)]\tLoss: {:.6f}'.format(
epoch, batch_idx * len(data),
len(self.train_loader.dataset),
100. * batch_idx / len(self.train_loader),
loss.item() / len(next_obs)))
if not from_rl:
zs = np.array(zs)
self.model.dist_mu = zs.mean(axis=0)
self.model.dist_std = zs.std(axis=0)
self.eval_statistics['train/log prob'] = np.mean(log_probs)
self.eval_statistics['train/KL'] = np.mean(kles)
self.eval_statistics['train/loss'] = np.mean(losses)
def debug_statistics(self):
"""
Given an image $$x$$, samples a bunch of latents from the prior
$$z_i$$ and decode them $$\hat x_i$$.
Compare this to $$\hat x$$, the reconstruction of $$x$$.
Ideally
- All the $$\hat x_i$$s do worse than $$\hat x$$ (makes sure VAE
isn’t ignoring the latent)
- Some $$\hat x_i$$ do better than other $$\hat x_i$$ (tests for
coverage)
"""
debug_batch_size = 64
data = self.get_batch(train=False)
reconstructions, _, _ = self.model(data)
img = data[0]
recon_mse = ((reconstructions[0] - img)**2).mean().view(-1)
img_repeated = img.expand((debug_batch_size, img.shape[0]))
samples = ptu.randn(debug_batch_size, self.representation_size)
random_imgs, _ = self.model.decode(samples)
random_mses = (random_imgs - img_repeated)**2
mse_improvement = ptu.get_numpy(random_mses.mean(dim=1) - recon_mse)
stats = create_stats_ordered_dict(
'debug/MSE improvement over random',
mse_improvement,
)
stats.update(
create_stats_ordered_dict(
'debug/MSE of random decoding',
ptu.get_numpy(random_mses),
))
stats['debug/MSE of reconstruction'] = ptu.get_numpy(recon_mse)[0]
if self.skew_dataset:
stats.update(
create_stats_ordered_dict('train weight', self._train_weights))
return stats
def compute_p_x_np_to_np(model,
data,
power,
decoder_distribution='bernoulli',
num_latents_to_sample=1,
sampling_method='importance_sampling'):
assert data.dtype == np.float64, 'images should be normalized'
assert power >= -1 and power <= 0, 'power for skew-fit should belong to [-1, 0]'
log_p, log_q, log_d = compute_log_p_log_q_log_d(model, data,
decoder_distribution,
num_latents_to_sample,
sampling_method)
if sampling_method == 'importance_sampling':
log_p_x = (log_p - log_q + log_d).mean(dim=1)
elif sampling_method == 'biased_sampling' or sampling_method == 'true_prior_sampling':
log_p_x = log_d.mean(dim=1)
else:
raise EnvironmentError('Invalid Sampling Method Provided')
log_p_x_skewed = power * log_p_x
return ptu.get_numpy(log_p_x_skewed)
def train_from_torch(self, batch):
rewards = batch['rewards']
terminals = batch['terminals']
obs = batch['observations']
actions = batch['actions']
next_obs = batch['next_observations']
"""
Policy and Alpha Loss
"""
new_obs_actions, policy_mean, policy_log_std, log_pi, *_ = self.policy(
obs, reparameterize=True, return_log_prob=True,
)
if self.use_automatic_entropy_tuning:
alpha_loss = -(self.log_alpha * (log_pi + self.target_entropy).detach()).mean()
self.alpha_optimizer.zero_grad()
alpha_loss.backward()
self.alpha_optimizer.step()
alpha = self.log_alpha.exp()
else:
alpha_loss = 0
alpha = 1
q_new_actions = torch.min(
self.qf1(obs, new_obs_actions),
self.qf2(obs, new_obs_actions),
)
policy_loss = (alpha*log_pi - q_new_actions).mean()
"""
QF Loss
"""
q1_pred = self.qf1(obs, actions)
q2_pred = self.qf2(obs, actions)
# Make sure policy accounts for squashing functions like tanh correctly!
new_next_actions, _, _, new_log_pi, *_ = self.policy(
next_obs, reparameterize=True, return_log_prob=True,
)
target_q_values = torch.min(
self.target_qf1(next_obs, new_next_actions),
self.target_qf2(next_obs, new_next_actions),
) - alpha * new_log_pi
q_target = self.reward_scale * rewards + (1. - terminals) * self.discount * target_q_values
qf1_loss = self.qf_criterion(q1_pred, q_target.detach())
qf2_loss = self.qf_criterion(q2_pred, q_target.detach())
"""
Update networks
"""
self.qf1_optimizer.zero_grad()
qf1_loss.backward()
self.qf1_optimizer.step()
self.qf2_optimizer.zero_grad()
qf2_loss.backward()
self.qf2_optimizer.step()
self.policy_optimizer.zero_grad()
policy_loss.backward()
self.policy_optimizer.step()
"""
Soft Updates
"""
if self._n_train_steps_total % self.target_update_period == 0:
ptu.soft_update_from_to(
self.qf1, self.target_qf1, self.soft_target_tau
)
ptu.soft_update_from_to(
self.qf2, self.target_qf2, self.soft_target_tau
)
"""
Save some statistics for eval
"""
if self._need_to_update_eval_statistics:
self._need_to_update_eval_statistics = False
"""
Eval should set this to None.
This way, these statistics are only computed for one batch.
"""
policy_loss = (log_pi - q_new_actions).mean()
self.eval_statistics['QF1 Loss'] = np.mean(ptu.get_numpy(qf1_loss))
self.eval_statistics['QF2 Loss'] = np.mean(ptu.get_numpy(qf2_loss))
self.eval_statistics['Policy Loss'] = np.mean(ptu.get_numpy(
policy_loss
))
self.eval_statistics.update(create_stats_ordered_dict(
'Q1 Predictions',
ptu.get_numpy(q1_pred),
))
self.eval_statistics.update(create_stats_ordered_dict(
'Q2 Predictions',
ptu.get_numpy(q2_pred),
))
self.eval_statistics.update(create_stats_ordered_dict(
'Q Targets',
ptu.get_numpy(q_target),
))
self.eval_statistics.update(create_stats_ordered_dict(
'Log Pis',
ptu.get_numpy(log_pi),
))
self.eval_statistics.update(create_stats_ordered_dict(
'Policy mu',
ptu.get_numpy(policy_mean),
))
self.eval_statistics.update(create_stats_ordered_dict(
'Policy log std',
ptu.get_numpy(policy_log_std),
))
if self.use_automatic_entropy_tuning:
self.eval_statistics['Alpha'] = alpha.item()
self.eval_statistics['Alpha Loss'] = alpha_loss.item()
self._n_train_steps_total += 1
def train_from_torch(self, batch):
rewards = batch['rewards']
terminals = batch['terminals']
obs = batch['observations']
actions = batch['actions']
next_obs = batch['next_observations']
"""
Critic operations.
"""
next_actions = self.target_policy(next_obs)
noise = ptu.randn(next_actions.shape) * self.target_policy_noise
noise = torch.clamp(noise, -self.target_policy_noise_clip,
self.target_policy_noise_clip)
noisy_next_actions = next_actions + noise
target_q1_values = self.target_qf1(next_obs, noisy_next_actions)
target_q2_values = self.target_qf2(next_obs, noisy_next_actions)
target_q_values = torch.min(target_q1_values, target_q2_values)
q_target = self.reward_scale * rewards + (
1. - terminals) * self.discount * target_q_values
q_target = q_target.detach()
q1_pred = self.qf1(obs, actions)
bellman_errors_1 = (q1_pred - q_target)**2
qf1_loss = bellman_errors_1.mean()
q2_pred = self.qf2(obs, actions)
bellman_errors_2 = (q2_pred - q_target)**2
qf2_loss = bellman_errors_2.mean()
"""
Update Networks
"""
self.qf1_optimizer.zero_grad()
qf1_loss.backward()
self.qf1_optimizer.step()
self.qf2_optimizer.zero_grad()
qf2_loss.backward()
self.qf2_optimizer.step()
policy_actions = policy_loss = None
if self._n_train_steps_total % self.policy_and_target_update_period == 0:
policy_actions = self.policy(obs)
q_output = self.qf1(obs, policy_actions)
policy_loss = -q_output.mean()
self.policy_optimizer.zero_grad()
policy_loss.backward()
self.policy_optimizer.step()
ptu.soft_update_from_to(self.policy, self.target_policy, self.tau)
ptu.soft_update_from_to(self.qf1, self.target_qf1, self.tau)
ptu.soft_update_from_to(self.qf2, self.target_qf2, self.tau)
if self._need_to_update_eval_statistics:
self._need_to_update_eval_statistics = False
if policy_loss is None:
policy_actions = self.policy(obs)
q_output = self.qf1(obs, policy_actions)
policy_loss = -q_output.mean()
self.eval_statistics['QF1 Loss'] = np.mean(ptu.get_numpy(qf1_loss))
self.eval_statistics['QF2 Loss'] = np.mean(ptu.get_numpy(qf2_loss))
self.eval_statistics['Policy Loss'] = np.mean(
ptu.get_numpy(policy_loss))
self.eval_statistics.update(
create_stats_ordered_dict(
'Q1 Predictions',
ptu.get_numpy(q1_pred),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Q2 Predictions',
ptu.get_numpy(q2_pred),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Q Targets',
ptu.get_numpy(q_target),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Bellman Errors 1',
ptu.get_numpy(bellman_errors_1),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Bellman Errors 2',
ptu.get_numpy(bellman_errors_2),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Policy Action',
ptu.get_numpy(policy_actions),
))
self._n_train_steps_total += 1
def test_epoch(
self,
epoch,
save_reconstruction=True,
save_vae=True,
from_rl=False,
):
self.model.eval()
losses = []
log_probs = []
kles = []
zs = []
beta = float(self.beta_schedule.get_value(epoch))
for batch_idx in range(10):
next_obs = self.get_batch(train=False)
reconstructions, obs_distribution_params, latent_distribution_params = self.model(
next_obs)
log_prob = self.model.logprob(next_obs, obs_distribution_params)
kle = self.model.kl_divergence(latent_distribution_params)
loss = -1 * log_prob + beta * kle
encoder_mean = latent_distribution_params[0]
z_data = ptu.get_numpy(encoder_mean.cpu())
for i in range(len(z_data)):
zs.append(z_data[i, :])
losses.append(loss.item())
log_probs.append(log_prob.item())
kles.append(kle.item())
if batch_idx == 0 and save_reconstruction:
n = min(next_obs.size(0), 8)
comparison = torch.cat([
next_obs[:n].narrow(start=0, length=self.imlength,
dim=1).contiguous().view(
-1, self.input_channels,
self.imsize,
self.imsize).transpose(2, 3),
reconstructions.view(
self.batch_size,
self.input_channels,
self.imsize,
self.imsize,
)[:n].transpose(2, 3)
])
save_dir = osp.join(logger.get_snapshot_dir(),
'r%d.png' % epoch)
save_image(comparison.data.cpu(), save_dir, nrow=n)
zs = np.array(zs)
self.eval_statistics['epoch'] = epoch
self.eval_statistics['test/log prob'] = np.mean(log_probs)
self.eval_statistics['test/KL'] = np.mean(kles)
self.eval_statistics['test/loss'] = np.mean(losses)
self.eval_statistics['beta'] = beta
if not from_rl:
for k, v in self.eval_statistics.items():
logger.record_tabular(k, v)
logger.dump_tabular()
if save_vae:
logger.save_itr_params(epoch, self.model)
def train_from_torch(self, batch):
rewards = batch['rewards']
terminals = batch['terminals']
obs = batch['observations']
actions = batch['actions']
next_obs = batch['next_observations']
"""
Policy operations.
"""
if self.policy_pre_activation_weight > 0:
policy_actions, pre_tanh_value = self.policy(
obs,
return_preactivations=True,
)
pre_activation_policy_loss = ((pre_tanh_value**2).sum(
dim=1).mean())
q_output = self.qf(obs, policy_actions)
raw_policy_loss = -q_output.mean()
policy_loss = (
raw_policy_loss +
pre_activation_policy_loss * self.policy_pre_activation_weight)
else:
policy_actions = self.policy(obs)
q_output = self.qf(obs, policy_actions)
raw_policy_loss = policy_loss = -q_output.mean()
"""
Critic operations.
"""
next_actions = self.target_policy(next_obs)
# speed up computation by not backpropping these gradients
next_actions.detach()
target_q_values = self.target_qf(
next_obs,
next_actions,
)
q_target = rewards + (1. - terminals) * self.discount * target_q_values
q_target = q_target.detach()
q_target = torch.clamp(q_target, self.min_q_value, self.max_q_value)
q_pred = self.qf(obs, actions)
bellman_errors = (q_pred - q_target)**2
raw_qf_loss = self.qf_criterion(q_pred, q_target)
if self.qf_weight_decay > 0:
reg_loss = self.qf_weight_decay * sum(
torch.sum(param**2)
for param in self.qf.regularizable_parameters())
qf_loss = raw_qf_loss + reg_loss
else:
qf_loss = raw_qf_loss
"""
Update Networks
"""
self.policy_optimizer.zero_grad()
policy_loss.backward()
self.policy_optimizer.step()
self.qf_optimizer.zero_grad()
qf_loss.backward()
self.qf_optimizer.step()
self._update_target_networks()
"""
Save some statistics for eval using just one batch.
"""
if self._need_to_update_eval_statistics:
self._need_to_update_eval_statistics = False
self.eval_statistics['QF Loss'] = np.mean(ptu.get_numpy(qf_loss))
self.eval_statistics['Policy Loss'] = np.mean(
ptu.get_numpy(policy_loss))
self.eval_statistics['Raw Policy Loss'] = np.mean(
ptu.get_numpy(raw_policy_loss))
self.eval_statistics['Preactivation Policy Loss'] = (
self.eval_statistics['Policy Loss'] -
self.eval_statistics['Raw Policy Loss'])
self.eval_statistics.update(
create_stats_ordered_dict(
'Q Predictions',
ptu.get_numpy(q_pred),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Q Targets',
ptu.get_numpy(q_target),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Bellman Errors',
ptu.get_numpy(bellman_errors),
))
self.eval_statistics.update(
create_stats_ordered_dict(
'Policy Action',
ptu.get_numpy(policy_actions),
))
self._n_train_steps_total += 1
def _encode(self, imgs):
latent_distribution_params = self.vae.encode(ptu.from_numpy(imgs))
return ptu.get_numpy(latent_distribution_params[0])
def _decode(self, latents):
reconstructions, _ = self.vae.decode(ptu.from_numpy(latents))
decoded = ptu.get_numpy(reconstructions)
return decoded
def np_ify(tensor_or_other):
if isinstance(tensor_or_other, torch.autograd.Variable):
return ptu.get_numpy(tensor_or_other)
else:
return tensor_or_other