From c4283ced6fa9699ac94fe598a6dac935efc0d7f4 Mon Sep 17 00:00:00 2001
From: VedantDave <vedant.dave@unileoben.ac.at>
Date: Sun, 9 Apr 2023 18:23:16 +0200
Subject: [PATCH] Changing CLUB loss and Tensor stacking

---
 DPI/models.py | 97 ++++++++++++++++++++++++++++++++-------------------
 1 file changed, 62 insertions(+), 35 deletions(-)

diff --git a/DPI/models.py b/DPI/models.py
index 72bb7b4..2158ea7 100644
--- a/DPI/models.py
+++ b/DPI/models.py
@@ -194,6 +194,27 @@ class TransitionModel(nn.Module):
         prior = {"mean": state_prior_mean, "std": state_prior_std, "sample": sample_state_prior, "history": history, "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):
+            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 reparemeterize(self, mean, std):
         eps = torch.randn_like(std)
         return mean + eps * std
@@ -227,40 +248,6 @@ class TanhBijector(torch.distributions.Transform):
         return 2.0 * (torch.log(torch.tensor([2.0])) - x - F.softplus(-2.0 * x))
      
 
-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, 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, 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):
-        mu, logvar = self.get_mu_logvar(x_samples)
-        return - self.loglikeli(x_samples, y_samples)
-    
-
 class ProjectionHead(nn.Module):
     def __init__(self, state_size, action_size, hidden_size):
         super(ProjectionHead, self).__init__()
@@ -294,4 +281,44 @@ class ContrastiveHead(nn.Module):
         logits = torch.matmul(z_a, Wz)  # (B,B)
         logits = logits - torch.max(logits, 1)[0][:, None]
         logits = logits * self.temperature
-        return logits
\ No newline at end of file
+        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__()
+        self.last_states = last_states
+        self.current_states = current_states
+        self.negative_current_states = negative_current_states
+        self.predicted_current_states = predicted_current_states
+
+    def get_mu_var_samples(self, state_dict):
+        dist = state_dict["distribution"]
+        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
+        
+    def loglikeli(self):
+        _, _, pred_sample = self.get_mu_var_samples(self.predicted_current_states)
+        mu_curr, var_curr, _ = self.get_mu_var_samples(self.current_states)
+        logvar_curr = torch.log(var_curr)    
+        return (-(mu_curr - pred_sample)**2 /var_curr-logvar_curr).sum(dim=1).mean(dim=0)
+
+    def forward(self):
+        _, _, pred_sample = self.get_mu_var_samples(self.predicted_current_states)
+        mu_curr, var_curr, _ = self.get_mu_var_samples(self.current_states)
+        mu_neg, var_neg, _ = self.get_mu_var_samples(self.negative_current_states)
+        
+        pos = (-(mu_curr - pred_sample)**2 /var_curr).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()
+    
+
+if "__name__ == __main__":
+    pass
\ No newline at end of file