Adding some new things

DPI/models.py

@@ -13,7 +13,7 @@ class ObservationEncoder(nn.Module):
         assert len(obs_shape) == 3
 
         self.state_size = state_size
-
+        
         layers = []
         for i in range(num_layers):
             input_channels = obs_shape[0] if i == 0 else output_channels
@@ -23,23 +23,24 @@ class ObservationEncoder(nn.Module):
 
         self.convs = nn.Sequential(*layers)
 
-        self.fc = nn.Linear(256 * 3 * 3, 2 * state_size)
+        self.fc = nn.Linear(256 * obs_shape[0], 2 * state_size)    # 9 if 3 frames stacked
 
     def forward(self, x):
-        x = self.convs(x)
+        x_reshaped = x.reshape(-1, *x.shape[-3:])
-        x = x.view(x.size(0), -1)
+        x_embed = self.convs(x_reshaped)
-        x = self.fc(x)
+        x_embed = torch.reshape(x_embed, (*x.shape[:-3], -1))
+        x = self.fc(x_embed)
         
         # Mean and standard deviation
         mean, std = torch.chunk(x, 2, dim=-1)
+        mean = nn.ELU()(mean)
         std = F.softplus(std)
-        std = torch.clamp(std, min=0.0, max=1e5)
+        std = torch.clamp(std, min=0.0, max=1e1)
 
         # Normal Distribution
         dist = self.get_dist(mean, std)
 
         # Sampling via reparameterization Trick
-        #x = dist.rsample()
         x = self.reparameterize(mean, std)
 
         encoded_output = {"sample": x, "distribution": dist}
@@ -63,7 +64,7 @@ class ObservationDecoder(nn.Module):
         self.output_shape = output_shape
         self.input_size = 256 * 3 * 3
         self.in_channels = [self.input_size, 256, 128, 64]
-        self.out_channels = [256, 128, 64, 3]
+        self.out_channels = [256, 128, 64, 9]
 
         if output_shape[1] == 84:
             self.kernels = [5, 7, 5, 6]
@@ -94,43 +95,50 @@ class ObservationDecoder(nn.Module):
 
 
 class Actor(nn.Module):
-    def __init__(self, state_size, hidden_size, action_size, num_layers=5):
+    def __init__(self, state_size, hidden_size, action_size, num_layers=4, min_std=1e-4, init_std=5, mean_scale=5):
         super().__init__()
         self.state_size = state_size    
         self.hidden_size = hidden_size
         self.action_size = action_size
         self.num_layers = num_layers
 
-        self._min_std=torch.Tensor([1e-4])[0]
+        self._min_std = min_std
-        self._init_std=torch.Tensor([5])[0]
+        self._init_std = init_std
-        self._mean_scale=torch.Tensor([5])[0]
+        self._mean_scale = mean_scale
 
         layers = []
         for i in range(self.num_layers):
             input_channels = state_size if i == 0 else self.hidden_size
-            output_channels = self.hidden_size if i!= self.num_layers-1 else 2*action_size
+            layers.append(nn.Linear(input_channels, self.hidden_size))
-            layers.append(nn.Linear(input_channels, output_channels))
+            layers.append(nn.ReLU())
-            layers.append(nn.LeakyReLU())
+        layers.append(nn.Linear(self.hidden_size, 2*self.action_size))
         self.action_model = nn.Sequential(*layers)
 
     def get_dist(self, mean, std):
         distribution = torch.distributions.Normal(mean, std)
         distribution = torch.distributions.transformed_distribution.TransformedDistribution(distribution, TanhBijector())
         distribution = torch.distributions.independent.Independent(distribution, 1)
+        distribution = SampleDist(distribution)
         return distribution
     
+    def add_exploration(self, action, action_noise=0.3):
+        return torch.clamp(torch.distributions.Normal(action, action_noise).rsample(), -1, 1)
+    
     def forward(self, features):
         out = self.action_model(features)
         mean, std = torch.chunk(out, 2, dim=-1) 
         
-        raw_init_std = torch.log(torch.exp(self._init_std) - 1)
+        raw_init_std = np.log(np.exp(self._init_std) - 1)
         action_mean = self._mean_scale * torch.tanh(mean / self._mean_scale)
         action_std = F.softplus(std + raw_init_std) + self._min_std
 
         dist = self.get_dist(action_mean, action_std)
-        sample = dist.rsample()
+        sample = dist.rsample() #self.reparameterize(action_mean, action_std)
         return sample
-        
+    
+    def reparameterize(self, mu, std):
+        eps = torch.randn_like(std)
+        return mu + eps * std
 
 class ValueModel(nn.Module):
     def __init__(self, state_size, hidden_size, num_layers=4):
@@ -140,11 +148,12 @@ class ValueModel(nn.Module):
         self.num_layers = num_layers
 
         layers = []
-        for i in range(self.num_layers):
+        for i in range(self.num_layers-1):
             input_channels = state_size if i == 0 else self.hidden_size
-            output_channels = self.hidden_size if i!= self.num_layers-1 else 1
+            output_channels = self.hidden_size
             layers.append(nn.Linear(input_channels, output_channels))
             layers.append(nn.LeakyReLU())
+        layers.append(nn.Linear(self.hidden_size, int(np.prod(1))))
         self.value_model = nn.Sequential(*layers) 
 
     def forward(self, state):
@@ -169,6 +178,7 @@ class RewardModel(nn.Module):
         return torch.distributions.independent.Independent(
                 torch.distributions.Normal(reward, 1), 1)
 
+"""
 class TransitionModel(nn.Module):
     def __init__(self, state_size, hidden_size, action_size, history_size):
         super().__init__()
@@ -180,6 +190,7 @@ class TransitionModel(nn.Module):
         self.act_fn = nn.LeakyReLU()
 
         self.fc_state_action = nn.Linear(state_size + action_size, hidden_size)
+        self.ln = nn.LayerNorm(hidden_size)
         self.history_cell = nn.GRUCell(hidden_size + history_size, history_size)
         self.fc_state_prior  = nn.Linear(history_size + state_size + action_size, 2 * state_size)
         self.fc_state_posterior = nn.Linear(history_size + state_size + action_size, 2 * state_size)
@@ -194,12 +205,25 @@ class TransitionModel(nn.Module):
         distribution = torch.distributions.independent.Independent(distribution, 1)
         return distribution
 
-    def imagine_step(self, prev_state, prev_action, prev_history):
+    def stack_states(self, states, dim=0):        
-        state_action = self.act_fn(self.fc_state_action(torch.cat([prev_state, prev_action], dim=-1)))
+        s = dict(
-        prev_hist = prev_history.detach()
+            mean = torch.stack([state['mean'] for state in states], dim=dim),
-        history = self.history_cell(torch.cat([state_action, prev_hist], dim=-1), prev_hist)
+            std  = torch.stack([state['std'] for state in states], dim=dim),
-
+            sample = torch.stack([state['sample'] for state in states], dim=dim),
-        state_prior = self.fc_state_prior(torch.cat([history, prev_state, prev_action], dim=-1))
+            history = torch.stack([state['history'] for state in states], dim=dim),)
+        if 'distribution' in states:
+            dist = dict(distribution = [state['distribution'] for state in states])
+            s.update(dist)
+        return s
+    
+    def seq_to_batch(self, state, name):
+        return dict(
+            sample = torch.reshape(state[name], (state[name].shape[0]* state[name].shape[1], *state[name].shape[2:])))
+    
+    def imagine_step(self, state, action, history):
+        state_action = self.ln(self.act_fn(self.fc_state_action(torch.cat([state, action], dim=-1))))
+        imag_hist = self.history_cell(torch.cat([state_action, history], dim=-1), history)
+        state_prior = self.fc_state_prior(torch.cat([imag_hist, state, action], dim=-1))
         state_prior_mean, state_prior_std = torch.chunk(state_prior, 2, dim=-1)
         state_prior_std = F.softplus(state_prior_std)
 
@@ -208,19 +232,9 @@ class TransitionModel(nn.Module):
 
         # Sampling via reparameterization Trick
         sample_state_prior = self.reparemeterize(state_prior_mean, state_prior_std)
-        prior = {"mean": state_prior_mean, "std": state_prior_std, "sample": sample_state_prior, "history": history, "distribution": state_prior_dist}
+        prior = {"mean": state_prior_mean, "std": state_prior_std, "sample": sample_state_prior, "history": imag_hist, "distribution": state_prior_dist}
         return prior
     
-    def stack_states(self, states, dim=0):        
-        s = dict(
-            mean = torch.stack([state['mean'] for state in states], dim=dim),
-            std  = torch.stack([state['std'] for state in states], dim=dim),
-            sample = torch.stack([state['sample'] for state in states], dim=dim),
-            history = torch.stack([state['history'] for state in states], dim=dim),)
-        dist = dict(distribution = [state['distribution'] for state in states])
-        s.update(dist)
-        return s
-    
     def imagine_rollout(self, state, action, history, horizon):
         imagined_priors = []
         for i in range(horizon):
@@ -231,10 +245,126 @@ class TransitionModel(nn.Module):
         imagined_priors = self.stack_states(imagined_priors, dim=0)
         return imagined_priors
     
+    def observe_step(self, prev_state, prev_action, prev_history, nonterms):
+        state_action = self.ln(self.act_fn(self.fc_state_action(torch.cat([prev_state, prev_action], dim=-1))))
+        current_history = self.history_cell(torch.cat([state_action, prev_history], dim=-1), prev_history)
+        state_prior = self.fc_state_prior(torch.cat([prev_history, prev_state, prev_action], dim=-1))
+        state_prior_mean, state_prior_std = torch.chunk(state_prior*nonterms, 2, dim=-1)
+        state_prior_std = F.softplus(state_prior_std) + 0.1
+        sample_state_prior = state_prior_mean + torch.randn_like(state_prior_mean) * state_prior_std
+        prior = {"mean": state_prior_mean, "std": state_prior_std, "sample": sample_state_prior, "history": current_history}
+        return prior
+
+    def observe_rollout(self, rollout_states, rollout_actions, init_history, nonterms):
+        observed_rollout = []
+        for i in range(rollout_states.shape[0]):
+            actions = rollout_actions[i] * nonterms[i]
+            prior = self.observe_step(rollout_states[i], actions, init_history, nonterms[i])
+            init_history = prior["history"]
+            observed_rollout.append(prior)
+        observed_rollout = self.stack_states(observed_rollout, dim=0)
+        return observed_rollout
+
     def reparemeterize(self, mean, std):
         eps = torch.randn_like(std)
         return mean + eps * std
+"""
 
+class TransitionModel(nn.Module):
+    def __init__(self, state_size, hidden_size, action_size, history_size):
+        super().__init__()
+
+        self.state_size = state_size
+        self.hidden_size = hidden_size
+        self.action_size = action_size
+        self.history_size = history_size
+        self.act_fn = nn.ELU()
+
+        self.fc_state_action = nn.Linear(state_size + action_size, hidden_size)
+        self.history_cell = nn.GRUCell(hidden_size, history_size)
+        self.fc_state_mu = nn.Linear(history_size + hidden_size, state_size)
+        self.fc_state_sigma = nn.Linear(history_size + hidden_size, state_size)
+
+        self.batch_norm = nn.BatchNorm1d(hidden_size)
+        self.batch_norm2 = nn.BatchNorm1d(state_size)
+
+        self.min_sigma = 1e-4
+        self.max_sigma = 1e0
+
+    def init_states(self, batch_size, device):
+        self.prev_state = torch.zeros(batch_size, self.state_size).to(device)
+        self.prev_action = torch.zeros(batch_size, self.action_size).to(device)
+        self.prev_history = torch.zeros(batch_size, self.history_size).to(device)
+            
+    def get_dist(self, mean, std):
+        distribution = torch.distributions.Normal(mean, std)
+        distribution = torch.distributions.independent.Independent(distribution, 1)
+        return distribution
+
+    def stack_states(self, states, dim=0):        
+        s = dict(
+            mean = torch.stack([state['mean'] for state in states], dim=dim),
+            std  = torch.stack([state['std'] for state in states], dim=dim),
+            sample = torch.stack([state['sample'] for state in states], dim=dim),
+            history = torch.stack([state['history'] for state in states], dim=dim),)
+        if 'distribution' in states:
+            dist = dict(distribution = [state['distribution'] for state in states])
+            s.update(dist)
+        return s
+    
+    def seq_to_batch(self, state, name):
+        return dict(
+            sample = torch.reshape(state[name], (state[name].shape[0]* state[name].shape[1], *state[name].shape[2:])))
+    
+    def imagine_step(self, state, action, history):
+        next_state_action_enc = self.act_fn(self.batch_norm(self.fc_state_action(torch.cat([state, action], dim=-1))))
+        imag_history = self.history_cell(next_state_action_enc, history)
+        next_state_mu = self.act_fn(self.batch_norm2(self.fc_state_mu(torch.cat([next_state_action_enc, imag_history], dim=-1))))
+        next_state_sigma = torch.sigmoid(self.fc_state_sigma(torch.cat([next_state_action_enc, imag_history], dim=-1)))
+        next_state_sigma = self.min_sigma + (self.max_sigma - self.min_sigma) * next_state_sigma
+
+        # Normal Distribution
+        next_state_dist = self.get_dist(next_state_mu, next_state_sigma)
+        next_state_sample = self.reparemeterize(next_state_mu, next_state_sigma)
+        prior = {"mean": next_state_mu, "std": next_state_sigma, "sample": next_state_sample, "history": imag_history, "distribution": next_state_dist}
+        return prior
+    
+    def imagine_rollout(self, state, action, history, horizon):
+        imagined_priors = []
+        for i in range(horizon):
+            prior = self.imagine_step(state, action, history)
+            state = prior["sample"]
+            history = prior["history"]
+            imagined_priors.append(prior)
+        imagined_priors = self.stack_states(imagined_priors, dim=0)
+        return imagined_priors
+    
+    def observe_step(self, prev_state, prev_action, prev_history):
+        state_action_enc = self.act_fn(self.batch_norm(self.fc_state_action(torch.cat([prev_state, prev_action], dim=-1))))
+        current_history = self.history_cell(state_action_enc, prev_history)
+        state_mu = self.act_fn(self.batch_norm2(self.fc_state_mu(torch.cat([state_action_enc, prev_history], dim=-1))))
+        state_sigma = F.softplus(self.fc_state_sigma(torch.cat([state_action_enc, prev_history], dim=-1)))
+
+        sample_state = state_mu + torch.randn_like(state_mu) * state_sigma
+        state_enc = {"mean": state_mu, "std": state_sigma, "sample": sample_state, "history": current_history}
+        return state_enc
+
+    def observe_rollout(self, rollout_states, rollout_actions, init_history, nonterms):
+        observed_rollout = []
+        for i in range(rollout_states.shape[0]):
+            rollout_states_ = rollout_states[i]
+            rollout_actions_ = rollout_actions[i]
+            init_history_ = nonterms[i] * init_history
+            state_enc = self.observe_step(rollout_states_, rollout_actions_, init_history_)
+            init_history = state_enc["history"]
+            observed_rollout.append(state_enc)
+        observed_rollout = self.stack_states(observed_rollout, dim=0)
+        return observed_rollout
+
+    def reparemeterize(self, mean, std):
+        eps = torch.randn_like(mean)
+        return mean + eps * std
+    
 
 class TanhBijector(torch.distributions.Transform):
     def __init__(self):
@@ -300,6 +430,7 @@ class ContrastiveHead(nn.Module):
         return logits
     
 
+"""
 class CLUBSample(nn.Module):  # Sampled version of the CLUB estimator
     def __init__(self, last_states, current_states, negative_current_states, predicted_current_states):
         super(CLUBSample, self).__init__()
@@ -313,7 +444,7 @@ class CLUBSample(nn.Module):  # Sampled version of the CLUB estimator
         sample = state_dict["sample"] #dist.sample()  # Use state_dict["sample"] if you want to use the same sample for all the losses
         mu = dist.mean
         var = dist.variance
-        return mu, var, sample
+        return mu.detach(), var.detach(), sample.detach()
         
     def loglikeli(self):
         _, _, pred_sample = self.get_mu_var_samples(self.predicted_current_states)
@@ -330,15 +461,136 @@ class CLUBSample(nn.Module):  # Sampled version of the CLUB estimator
         random_index = torch.randperm(sample_size).long()
 
         pos = (-(mu_curr - pred_sample)**2 /var_curr).sum(dim=1).mean(dim=0)
-        neg = (-(mu_curr - pred_sample[random_index])**2 /var_curr).sum(dim=1).mean(dim=0)
+        #neg = (-(mu_curr - pred_sample[random_index])**2 /var_curr).sum(dim=1).mean(dim=0)
-        #neg = (-(mu_neg - pred_sample)**2 /var_neg).sum(dim=1).mean(dim=0)
+        neg = (-(mu_neg - pred_sample)**2 /var_neg).sum(dim=1).mean(dim=0)
         upper_bound = pos - neg
 
         return upper_bound/2
 
     def learning_loss(self):
         return - self.loglikeli()
+"""
+
+class CLUBSample(nn.Module):  # Sampled version of the CLUB estimator
+    def __init__(self, x_dim, y_dim, hidden_size):
+        super(CLUBSample, self).__init__()
+        self.p_mu = nn.Sequential(nn.Linear(x_dim, hidden_size//2),
+                                       nn.ReLU(),
+                                       nn.Linear(hidden_size//2, y_dim))
+
+        self.p_logvar = nn.Sequential(nn.Linear(x_dim, hidden_size//2),
+                                       nn.ReLU(),
+                                       nn.Linear(hidden_size//2, y_dim),
+                                       nn.Tanh())
+
+    def get_mu_logvar(self, x_samples):
+        mu = self.p_mu(x_samples)
+        logvar = self.p_logvar(x_samples)
+        return mu, logvar
+     
+        
+    def loglikeli(self, x_samples, y_samples):
+        mu, logvar = self.get_mu_logvar(x_samples)
+        return (-(mu - y_samples)**2 /logvar.exp()-logvar).sum(dim=1).mean(dim=0)
     
 
+    def forward(self, x_samples, y_samples, y_negatives):
+        mu, logvar = self.get_mu_logvar(x_samples)
+        
+        sample_size = x_samples.shape[0]
+        #random_index = torch.randint(sample_size, (sample_size,)).long()
+        random_index = torch.randperm(sample_size).long()
+        
+        positive = -(mu - y_samples)**2 / logvar.exp()
+        #negative = - (mu - y_samples[random_index])**2 / logvar.exp()
+        negative = -(mu - y_negatives)**2 / logvar.exp()
+        upper_bound = (positive.sum(dim = -1) - negative.sum(dim = -1)).mean()
+        return upper_bound/2.
+
+    def learning_loss(self, x_samples, y_samples):
+        return -self.loglikeli(x_samples, y_samples)
+
+
+class QFunction(nn.Module):
+    """MLP for q-function."""
+    def __init__(self, obs_dim, action_dim, hidden_dim):
+        super().__init__()
+
+        self.trunk = nn.Sequential(
+            nn.Linear(obs_dim + action_dim, hidden_dim), nn.ReLU(),
+            nn.Linear(hidden_dim, hidden_dim), nn.ReLU(),
+            nn.Linear(hidden_dim, 1)
+        )
+
+    def forward(self, obs, action):
+        assert obs.size(0) == action.size(0)
+
+        obs_action = torch.cat([obs, action], dim=1)
+        return self.trunk(obs_action)
+
+
+class Critic(nn.Module):
+    """Critic network, employes two q-functions."""
+    def __init__(
+        self, obs_shape, action_shape, hidden_dim, encoder_feature_dim):
+        super().__init__()
+
+        self.Q1 = QFunction(
+            self.encoder.feature_dim, action_shape[0], hidden_dim
+        )
+        self.Q2 = QFunction(
+            self.encoder.feature_dim, action_shape[0], hidden_dim
+        )
+
+        self.outputs = dict()
+
+    def forward(self, obs, action, detach_encoder=False):
+        # detach_encoder allows to stop gradient propogation to encoder
+        obs = self.encoder(obs, detach=detach_encoder)
+
+        q1 = self.Q1(obs, action)
+        q2 = self.Q2(obs, action)
+
+        self.outputs['q1'] = q1
+        self.outputs['q2'] = q2
+
+        return q1, q2
+
+class SampleDist:
+    def __init__(self, dist, samples=100):
+        self._dist = dist
+        self._samples = samples
+
+    @property
+    def name(self):
+        return 'SampleDist'
+
+    def __getattr__(self, name):
+        return getattr(self._dist, name)
+
+    def mean(self):
+        sample = self._dist.rsample(self._samples)
+        return torch.mean(sample, 0)
+
+    def mode(self):
+        dist = self._dist.expand((self._samples, *self._dist.batch_shape))
+        sample = dist.rsample()
+        logprob = dist.log_prob(sample)
+        batch_size = sample.size(1)
+        feature_size = sample.size(2)
+        indices = torch.argmax(logprob, dim=0).reshape(1, batch_size, 1).expand(1, batch_size, feature_size)
+        return torch.gather(sample, 0, indices).squeeze(0)
+
+    def entropy(self):
+        dist = self._dist.expand((self._samples, *self._dist.batch_shape))
+        sample = dist.rsample()
+        logprob = dist.log_prob(sample)
+        return -torch.mean(logprob, 0)
+
+    def sample(self):
+        return self._dist.sample()
+
+
 if "__name__ == __main__":
-    pass
+    tr = TransitionModel(50, 512, 1, 256)
+

DPI/replay_buffer.py

@@ -0,0 +1,51 @@
+import torch
+import numpy as np
+
+
+class ReplayBuffer:
+
+    def __init__(self, size, obs_shape, action_size, seq_len, batch_size):
+        self.size = size
+        self.obs_shape = obs_shape
+        self.action_size = action_size
+        self.seq_len = seq_len
+        self.batch_size = batch_size
+        self.idx = 0
+        self.full = False
+        self.observations = np.empty((size, *obs_shape), dtype=np.uint8) 
+        self.next_observations = np.empty((size, *obs_shape), dtype=np.uint8)
+        self.actions = np.empty((size, action_size), dtype=np.float32)
+        self.rewards = np.empty((size,), dtype=np.float32) 
+        self.terminals = np.empty((size,), dtype=np.float32)
+        self.steps, self.episodes = 0, 0
+    
+    def add(self, obs, ac, next_obs, rew, done):
+        self.observations[self.idx] = obs
+        self.next_observations[self.idx] = next_obs
+        self.actions[self.idx] = ac
+        self.rewards[self.idx] = rew
+        self.terminals[self.idx] = done
+        self.idx = (self.idx + 1) % self.size
+        self.full = self.full or self.idx == 0
+        self.steps += 1 
+        self.episodes = self.episodes + (1 if done else 0)
+
+    def _sample_idx(self, L):
+        valid_idx = False
+        while not valid_idx:
+            idx = np.random.randint(0, self.size if self.full else self.idx - L)
+            idxs = np.arange(idx, idx + L) % self.size
+            valid_idx = not self.idx in idxs[1:] 
+        return idxs
+
+    def _retrieve_batch(self, idxs, n, L):
+        vec_idxs = idxs.transpose().reshape(-1)  # Unroll indices
+        observations = self.observations[vec_idxs]
+        next_observations = self.next_observations[vec_idxs]
+        return observations.reshape(L, n, *observations.shape[1:]),self.actions[vec_idxs].reshape(L, n, -1), next_observations.reshape(L, n, *next_observations.shape[1:]), self.rewards[vec_idxs].reshape(L, n), self.terminals[vec_idxs].reshape(L, n)
+
+    def sample(self):
+        n = self.batch_size
+        l = self.seq_len
+        obs,acs,nxt_obs,rews,terms= self._retrieve_batch(np.asarray([self._sample_idx(l) for _ in range(n)]), n, l)
+        return obs,acs,nxt_obs,rews,terms

DPI/train.py

@@ -48,10 +48,10 @@ def parse_args():
     parser.add_argument('--episode_length', default=51, type=int)
     # train
     parser.add_argument('--agent', default='dpi', type=str, choices=['baseline', 'bisim', 'deepmdp', 'db', 'dpi', 'rpc'])
-    parser.add_argument('--init_steps', default=10000, type=int)
+    parser.add_argument('--init_steps', default=5000, type=int)
     parser.add_argument('--num_train_steps', default=100000, type=int)
     parser.add_argument('--update_steps', default=100, type=int)
-    parser.add_argument('--batch_size', default=64, type=int)  #512
+    parser.add_argument('--batch_size', default=64, type=int) 
     parser.add_argument('--state_size', default=50, type=int)
     parser.add_argument('--hidden_size', default=512, type=int)
     parser.add_argument('--history_size', default=256, type=int)
@@ -66,20 +66,20 @@ def parse_args():
     parser.add_argument('--num_eval_episodes', default=20, type=int)
     parser.add_argument('--evaluation_interval', default=10000, type=int)  # TODO: master had 10000
     # value
-    parser.add_argument('--value_lr', default=1e-6, type=float)
+    parser.add_argument('--value_lr', default=8e-5, type=float)
     parser.add_argument('--value_target_update_freq', default=100, type=int)
     parser.add_argument('--td_lambda', default=0.95, type=int)
     # actor
-    parser.add_argument('--actor_lr', default=1e-6, type=float)
+    parser.add_argument('--actor_lr', default=8e-5, type=float)     
     parser.add_argument('--actor_beta', default=0.9, type=float)
     parser.add_argument('--actor_log_std_min', default=-10, type=float)
     parser.add_argument('--actor_log_std_max', default=2, type=float)
     parser.add_argument('--actor_update_freq', default=2, type=int)
     # world/encoder/decoder
     parser.add_argument('--encoder_type', default='pixel', type=str, choices=['pixel', 'pixelCarla096', 'pixelCarla098', 'identity'])
-    parser.add_argument('--world_model_lr', default=1e-5, type=float)
+    parser.add_argument('--world_model_lr', default=6e-5, type=float)
-    parser.add_argument('--decoder_lr', default=1e-5, type=float)
+    parser.add_argument('--decoder_lr', default=6e-4, type=float)
-    parser.add_argument('--reward_lr', default=1e-5, type=float)
+    parser.add_argument('--reward_lr', default=6e-5, type=float)
     parser.add_argument('--encoder_tau', default=0.001, type=float)
     parser.add_argument('--decoder_type', default='pixel', type=str, choices=['pixel', 'identity', 'contrastive', 'reward', 'inverse', 'reconstruction'])
     parser.add_argument('--num_layers', default=4, type=int)
@@ -157,16 +157,19 @@ class DPI:
                             obs_shape=(self.args.frame_stack*self.args.channels,self.args.image_size,self.args.image_size), # (9,84,84)
                             state_size=self.args.state_size # 128
                             ).to(device)
+        self.obs_encoder.apply(self.init_weights)
         
         self.obs_encoder_momentum = ObservationEncoder(
                             obs_shape=(self.args.frame_stack*self.args.channels,self.args.image_size,self.args.image_size), # (9,84,84)
                             state_size=self.args.state_size # 128
                             ).to(device)
+        self.obs_encoder_momentum.apply(self.init_weights)
 
         self.obs_decoder = ObservationDecoder(
                             state_size=self.args.state_size, # 128
                             output_shape=(self.args.channels*self.args.channels,self.args.image_size,self.args.image_size) # (3,84,84)
                             ).to(device)
+        self.obs_decoder.apply(self.init_weights)
 
         self.transition_model = TransitionModel(
                             state_size=self.args.state_size, # 128
@@ -174,6 +177,7 @@ class DPI:
                             action_size=self.env.action_space.shape[0], # 6
                             history_size=self.args.history_size, # 128
                             ).to(device)
+        self.transition_model.apply(self.init_weights)
         
         # Actor Model
         self.actor_model = Actor(
@@ -181,7 +185,7 @@ class DPI:
                             hidden_size=self.args.hidden_size, # 256, 
                             action_size=self.env.action_space.shape[0], # 6
                             ).to(device)
-        #self.actor_model.apply(self.init_weights)
+        self.actor_model.apply(self.init_weights)
 
 
         # Value Models
@@ -189,16 +193,19 @@ class DPI:
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
                             ).to(device)
+        self.value_model.apply(self.init_weights)
         
         self.target_value_model = ValueModel(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
                             ).to(device)
+        self.target_value_model.apply(self.init_weights)
 
         self.reward_model = RewardModel(
                             state_size=self.args.state_size, # 128
                             hidden_size=self.args.hidden_size, # 256
                             ).to(device)
+        self.reward_model.apply(self.init_weights)
         
         # Contrastive Models
         self.prjoection_head = ProjectionHead(
@@ -228,22 +235,21 @@ class DPI:
         self.world_model_parameters = list(self.obs_encoder.parameters()) + list(self.prjoection_head.parameters()) + \
                                       list(self.transition_model.parameters()) + list(self.club_sample.parameters()) + \
                                       list(self.contrastive_head.parameters())
-        self.past_transition_parameters = self.transition_model.parameters()
 
         # optimizers
         self.world_model_opt = torch.optim.Adam(self.world_model_parameters, self.args.world_model_lr,eps=1e-6)
-        self.value_opt = torch.optim.Adam(self.value_model.parameters(), self.args.value_lr,eps=1e-6)
+        self.value_opt = torch.optim.Adam(self.value_model.parameters(), self.args.value_lr,eps=1e-6, weight_decay=1e-5)
         self.actor_opt = torch.optim.Adam(self.actor_model.parameters(), self.args.actor_lr,eps=1e-6)
         self.decoder_opt = torch.optim.Adam(self.obs_decoder.parameters(), self.args.decoder_lr,eps=1e-6)
-        self.reward_opt = torch.optim.Adam(self.reward_model.parameters(), self.args.reward_lr,eps=1e-6)
+        self.reward_opt = torch.optim.Adam(self.reward_model.parameters(), self.args.reward_lr,eps=1e-6, weight_decay=1e-5)
 
         # Create Modules
-        self.world_model_modules = [self.obs_encoder, self.prjoection_head, self.transition_model, self.club_sample, self.contrastive_head]
+        self.world_model_modules = [self.obs_encoder, self.prjoection_head, self.transition_model, self.club_sample, self.contrastive_head, 
+                                    self.obs_encoder_momentum, self.prjoection_head_momentum]
         self.value_modules = [self.value_model]
         self.actor_modules = [self.actor_model]
         self.decoder_modules = [self.obs_decoder]
         self.reward_modules = [self.reward_model]
-        #self.decoder_modules = [self.obs_decoder]
 
         if use_saved:
             self._use_saved_models(saved_model_dir)
@@ -282,7 +288,8 @@ class DPI:
             with torch.no_grad():
                 obs_  = torch.tensor(obs.copy(), dtype=torch.float32)
                 obs_ = preprocess_obs(obs_).to(device)
-                state = self.get_features(obs_)["distribution"].rsample().unsqueeze(0)
+                #state = self.get_features(obs_)["sample"].unsqueeze(0)
+                state = self.get_features(obs_)["distribution"].rsample()
                 action = actor_model(state)
                 action = actor_model.add_exploration(action)
                 action = action.cpu().numpy()[0]
@@ -307,7 +314,7 @@ class DPI:
         initial_logs = OrderedDict()
         logger = Logger(logdir)
 
-        episodic_rews = self.collect_random_sequences(5000//args.action_repeat)
+        episodic_rews = self.collect_random_sequences(self.args.init_steps//args.action_repeat)
         self.global_step = self.data_buffer.steps
         
         initial_logs.update({
@@ -361,7 +368,8 @@ class DPI:
         """
 
     def collect_batch(self):
-        obs_, acs_, nxt_obs_, rews_, terms_ = self.data_buffer.sample()        
+        obs_, acs_, nxt_obs_, rews_, terms_ = self.data_buffer.sample()      
+
         obs = torch.tensor(obs_, dtype=torch.float32)[1:]
         last_obs = torch.tensor(obs_, dtype=torch.float32)[:-1]
         nxt_obs = torch.tensor(nxt_obs_, dtype=torch.float32)[1:]
@@ -427,7 +435,7 @@ class DPI:
         if step % self.args.logging_freq:
             writer.add_scalar('World Loss/World Loss', world_loss.detach().item(), step)
             writer.add_scalar('Main Models Loss/Encoder Loss', enc_loss.detach().item(), step)
-            writer.add_scalar('Main Models Loss/Decoder Loss', dec_loss, step)
+            writer.add_scalar('Main Models Loss/Decoder Loss', dec_loss.detach().item(), step)
             writer.add_scalar('Actor Critic Loss/Actor Loss', actor_loss.detach().item(), step)
             writer.add_scalar('Actor Critic Loss/Value Loss', value_loss.detach().item(), step)
             writer.add_scalar('Actor Critic Loss/Reward Loss', rew_loss.detach().item(), step)
@@ -440,31 +448,28 @@ class DPI:
         # get features
         self.last_state_feat = self.get_features(last_obs)
         self.curr_state_feat = self.get_features(curr_obs)
-        self.nxt_state_feat = self.get_features(nxt_obs, momentum=True)
+        self.nxt_state_feat = self.get_features(nxt_obs)
+        self.nxt_state_feat_lb = self.get_features(nxt_obs, momentum=True)
 
         # states
-        self.last_state_enc = self.last_state_feat["sample"]
+        self.last_state_enc = self.last_state_feat["distribution"].rsample() #self.last_state_feat["sample"]
-        self.curr_state_enc = self.curr_state_feat["sample"]
+        self.curr_state_enc = self.curr_state_feat["distribution"].rsample() #self.curr_state_feat["sample"]
-        self.nxt_state_enc = self.nxt_state_feat["sample"]
+        self.nxt_state_enc = self.nxt_state_feat["distribution"].rsample() #self.nxt_state_feat["sample"]
-        
+        self.nxt_state_enc_lb = self.nxt_state_feat_lb["distribution"].rsample() #self.nxt_state_feat_lb["sample"]  
-        # actions
-        actions = actions.clone()
-        nxt_actions = nxt_actions.clone()
-
-        # rewards
-        rewards = rewards.clone()
 
         # predict next states
         self.transition_model.init_states(self.args.batch_size, device) # (N,128)
         self.observed_rollout = self.transition_model.observe_rollout(self.last_state_enc, actions, self.transition_model.prev_history, nonterms)
         self.pred_curr_state_dist = self.transition_model.get_dist(self.observed_rollout["mean"], self.observed_rollout["std"])
-        self.pred_curr_state_enc = self.pred_curr_state_dist.mean
+        #print(self.observed_rollout["mean"][0][0])
+        self.pred_curr_state_enc = self.pred_curr_state_dist.rsample()  #self.observed_rollout["sample"]
 
         # encoder loss
         enc_loss = self._encoder_loss(self.curr_state_feat["distribution"], self.pred_curr_state_dist)
 
         # reward loss
         rew_dist = self.reward_model(self.curr_state_enc)
+        #print(torch.cat([rew_dist.mean[0], rewards[0]],dim=-1))
         rew_loss = -torch.mean(rew_dist.log_prob(rewards))
 
         # decoder loss
@@ -472,13 +477,19 @@ class DPI:
         dec_loss = -torch.mean(dec_dist.log_prob(nxt_obs))
 
         # upper bound loss
-        _, ub_loss = self._upper_bound_minimization(self.curr_state_enc,
+        past_ub_loss = 0
-                                                                  self.pred_curr_state_enc) 
+        for i in range(self.curr_state_enc.shape[0]):
+            _, ub_loss = self._upper_bound_minimization(self.curr_state_enc[i],
+                                                        self.pred_curr_state_enc[i])
+            ub_loss = ub_loss + past_ub_loss
+            past_ub_loss = ub_loss
+        ub_loss = ub_loss / self.curr_state_enc.shape[0]
+        ub_loss = 0.01 * ub_loss
 
         # lower bound loss
         # contrastive projection
         vec_anchor = self.pred_curr_state_enc.detach()
-        vec_positive = self.nxt_state_enc.detach()
+        vec_positive = self.nxt_state_enc_lb.detach()
         z_anchor = self.prjoection_head(vec_anchor, nxt_actions)
         z_positive = self.prjoection_head_momentum(vec_positive, nxt_actions)
 
@@ -489,7 +500,7 @@ class DPI:
             labels = torch.arange(logits.shape[0]).long().to(device)
             lb_loss = F.cross_entropy(logits, labels) + past_lb_loss
             past_lb_loss = lb_loss.detach().item()
-        lb_loss = -0.1 * lb_loss/(z_anchor.shape[0])
+        lb_loss = -0.01 * lb_loss/(z_anchor.shape[0])
         
         world_loss = enc_loss + ub_loss + lb_loss
 
@@ -497,20 +508,27 @@ class DPI:
 
     def actor_model_losses(self):
         with torch.no_grad():
-            curr_state_enc = self.transition_model.seq_to_batch(self.curr_state_feat, "sample")["sample"]
+            #curr_state_enc = self.curr_state_enc.reshape(self.args.episode_length-1,-1) #self.transition_model.seq_to_batch(self.curr_state_feat, "sample")["sample"]
-            curr_state_hist = self.transition_model.seq_to_batch(self.observed_rollout, "history")["sample"]
+            #curr_state_hist = self.observed_rollout["history"].reshape(self.args.episode_length-1,-1) #self.transition_model.seq_to_batch(self.observed_rollout, "history")["sample"]
+            curr_state_enc = self.curr_state_enc.reshape(-1, self.args.state_size)
+            curr_state_hist = self.observed_rollout["history"].reshape(-1, self.args.history_size)
 
-        with FreezeParameters(self.world_model_modules + self.decoder_modules + self.reward_modules):
+        with FreezeParameters(self.world_model_modules + self.decoder_modules + self.reward_modules + self.value_modules):
             imagine_horizon = self.args.imagine_horizon
-            action = self.actor_model(curr_state_enc)
+            action = self.actor_model(curr_state_enc.detach())
             self.imagined_rollout = self.transition_model.imagine_rollout(curr_state_enc, 
-                                                                     action, curr_state_hist,
+                                                                     action, curr_state_hist.detach(),
                                                                      imagine_horizon)
+            self.pred_nxt_state_dist = self.transition_model.get_dist(self.imagined_rollout["mean"], self.imagined_rollout["std"])
+            #print(self.imagined_rollout["mean"][0][0])
+            self.pred_nxt_state_enc = self.pred_nxt_state_dist.rsample() #self.transition_model.reparemeterize(self.imagined_rollout["mean"], self.imagined_rollout["std"])
             
         with FreezeParameters(self.world_model_modules + self.value_modules + self.decoder_modules + self.reward_modules):
-            imag_rewards = self.reward_model(self.imagined_rollout["sample"]).mean
+            imag_rewards_dist = self.reward_model(self.pred_nxt_state_enc)
-            imag_values = self.value_model(self.imagined_rollout["sample"]).mean
+            imag_values_dist = self.value_model(self.pred_nxt_state_enc)
-            discounts =  self.args.discount * torch.ones_like(imag_rewards).detach() 
+            imag_rewards = imag_rewards_dist.mean   
+            imag_values = imag_values_dist.mean
+            discounts =  self.args.discount * torch.ones_like(imag_rewards).detach()
 
         self.returns = self._compute_lambda_return(imag_rewards[:-1], 
                                                    imag_values[:-1], 
@@ -525,7 +543,7 @@ class DPI:
     def value_model_losses(self):
         # value loss
         with torch.no_grad():
-            value_feat = self.imagined_rollout["sample"][:-1].detach()
+            value_feat = self.pred_nxt_state_enc[:-1].detach()
             value_targ = self.returns.detach()
         value_dist = self.value_model(value_feat)
         value_loss = -torch.mean(self.discounts * value_dist.log_prob(value_targ).unsqueeze(-1))
@@ -596,15 +614,14 @@ class DPI:
                     obs = torch.tensor(obs.copy(), dtype=torch.float32).unsqueeze(0)
                     obs_processed = preprocess_obs(obs).to(device)
                     state = self.get_features(obs_processed)["distribution"].rsample()
-                    action = self.actor_model(state).cpu().detach().numpy().squeeze()       
+                    action = self.actor_model(state).cpu().detach().numpy().squeeze()     
-                        
                 next_obs, rew, done, _ = self.env.step(action)
                 rewards += rew
+                obs = next_obs
 
                 if self.args.save_video:
                     self.env.video.record(self.env)
                     self.env.video.save('/home/vedant/Curiosity/Curiosity/DPI/log/video/learned_model.mp4')
-                obs = next_obs
             obs = self.env.reset()
             episodic_rewards.append(rewards)
         print("Episodic rewards: ", episodic_rewards)
@@ -679,6 +696,19 @@ class DPI:
         return x
     
     def _compute_lambda_return(self, rewards, values, discounts, td_lam, last_value):
+        next_values = torch.cat([values[1:], last_value[None]], 0)
+        target = rewards + discounts * next_values * (1 - td_lam)
+        timesteps = list(range(rewards.shape[0] - 1, -1, -1))
+        outputs = []
+        accumulated_reward = last_value
+        for t in timesteps:
+            inp = target[t]
+            discount_factor = discounts[t]
+            accumulated_reward = inp + discount_factor * td_lam * accumulated_reward
+            outputs.append(accumulated_reward)
+        returns = torch.flip(torch.stack(outputs), [0])
+        return returns
+        """
         next_values = torch.cat([values[1:], last_value.unsqueeze(0)],0)  
         targets = rewards + discounts * next_values * (1-td_lam)
         rets =[]
@@ -690,6 +720,7 @@ class DPI:
 
         returns = torch.flip(torch.stack(rets), [0])
         return returns
+        """
     
     def lambda_return(self,imged_reward, value_pred, bootstrap, discount=0.99, lambda_=0.95):
         # Setting lambda=1 gives a discounted Monte Carlo return.
@@ -740,7 +771,7 @@ if __name__ == '__main__':
     device = torch.device('cuda:0' if torch.cuda.is_available() else 'cpu')
 
     step = 0
-    total_steps = 500000
+    total_steps = 1000000
     dpi = DPI(args)
     dpi.train(step,total_steps)
     dpi.evaluate()

DPI/utils.py

@@ -63,17 +63,6 @@ def make_dir(dir_path):
     return dir_path
 
 
-def preprocess_obs(obs, bits=5):
-    """Preprocessing image, see https://arxiv.org/abs/1807.03039."""
-    bins = 2**bits
-    assert obs.dtype == torch.float32
-    if bits < 8:
-        obs = torch.floor(obs / 2**(8 - bits))
-    obs = obs / bins
-    obs = obs + torch.rand_like(obs) / bins
-    obs = obs - 0.5
-    return obs
-
 
 class FrameStack(gym.Wrapper):
     def __init__(self, env, k):
@@ -338,8 +327,8 @@ def make_env(args):
     return env
 
 def shuffle_along_axis(a, axis):
-            idx = np.random.rand(*a.shape).argsort(axis=axis)
+    idx = np.random.rand(*a.shape).argsort(axis=axis)
-            return np.take_along_axis(a,idx,axis=axis)
+    return np.take_along_axis(a,idx,axis=axis)
 
 def preprocess_obs(obs):
     obs = (obs/255.0) - 0.5
@@ -374,6 +363,20 @@ def video_from_array(arr, high_noise, filename):
                 out.write(frame)
             out.release()
 
+def save_video(images):
+    """
+    Image shape is (T, C, H, W)
+    Example:(50, 3, 84, 84)
+    """
+    output_file = "output.avi"
+    fourcc = cv2.VideoWriter_fourcc(*'XVID')
+    fps = 2
+    height, width, channels = 84,84,3
+    out = cv2.VideoWriter(output_file, fourcc, fps, (width, height))
+    for image in images:
+        image = np.uint8(image.transpose((1, 2, 0)))
+        out.write(image)
+    out.release()
 
 class CorruptVideos:
     def __init__(self, dir_path):