Update to pytorch 0.4

Author: ikostrikov2

main.py

@@ -97,7 +97,7 @@ def get_value_loss(flat_params):
         for param in value_net.parameters():
             value_loss += param.pow(2).sum() * args.l2_reg
         value_loss.backward()
-        return (value_loss.data.double().numpy()[0], get_flat_grad_from(value_net).data.double().numpy())
+        return (value_loss.data.double().numpy(), get_flat_grad_from(value_net).data.double().numpy())
 
     flat_params, _, opt_info = scipy.optimize.fmin_l_bfgs_b(get_value_loss, get_flat_params_from(value_net).double().numpy(), maxiter=25)
     set_flat_params_to(value_net, torch.Tensor(flat_params))
@@ -108,7 +108,12 @@ def get_value_loss(flat_params):
     fixed_log_prob = normal_log_density(Variable(actions), action_means, action_log_stds, action_stds).data.clone()
 
     def get_loss(volatile=False):
-        action_means, action_log_stds, action_stds = policy_net(Variable(states, volatile=volatile))
+        if volatile:
+            with torch.no_grad():
+                action_means, action_log_stds, action_stds = policy_net(Variable(states))
+        else:
+            action_means, action_log_stds, action_stds = policy_net(Variable(states))
+                
         log_prob = normal_log_density(Variable(actions), action_means, action_log_stds, action_stds)
         action_loss = -Variable(advantages) * torch.exp(log_prob - Variable(fixed_log_prob))
         return action_loss.mean()

models.py

@@ -1,7 +1,6 @@
 import torch
 import torch.autograd as autograd
 import torch.nn as nn
-import torch.nn.functional as F
 
 
 class Policy(nn.Module):
@@ -21,8 +20,8 @@ def __init__(self, num_inputs, num_outputs):
         self.final_value = 0
 
     def forward(self, x):
-        x = F.tanh(self.affine1(x))
-        x = F.tanh(self.affine2(x))
+        x = torch.tanh(self.affine1(x))
+        x = torch.tanh(self.affine2(x))
 
         action_mean = self.action_mean(x)
         action_log_std = self.action_log_std.expand_as(action_mean)
@@ -41,8 +40,8 @@ def __init__(self, num_inputs):
         self.value_head.bias.data.mul_(0.0)
 
     def forward(self, x):
-        x = F.tanh(self.affine1(x))
-        x = F.tanh(self.affine2(x))
+        x = torch.tanh(self.affine1(x))
+        x = torch.tanh(self.affine2(x))
 
         state_values = self.value_head(x)
         return state_values

trpo.py

@@ -32,18 +32,18 @@ def linesearch(model,
                max_backtracks=10,
                accept_ratio=.1):
     fval = f(True).data
-    print("fval before", fval[0])
+    print("fval before", fval.item())
     for (_n_backtracks, stepfrac) in enumerate(.5**np.arange(max_backtracks)):
         xnew = x + stepfrac * fullstep
         set_flat_params_to(model, xnew)
         newfval = f(True).data
         actual_improve = fval - newfval
         expected_improve = expected_improve_rate * stepfrac
         ratio = actual_improve / expected_improve
-        print("a/e/r", actual_improve[0], expected_improve[0], ratio[0])
+        print("a/e/r", actual_improve.item(), expected_improve.item(), ratio.item())
 
-        if ratio[0] > accept_ratio and actual_improve[0] > 0:
-            print("fval after", newfval[0])
+        if ratio.item() > accept_ratio and actual_improve.item() > 0:
+            print("fval after", newfval.item())
             return True, xnew
     return False, x