* Fixing mean tracked loss

* Adding a PINA progress bar

pina/solvers/pinns/basepinn.py

@@ -126,8 +126,9 @@ class PINNInterface(SolverInterface, metaclass=ABCMeta):
         # clamp unknown parameters in InverseProblem (if needed)
         self._clamp_params()
 
-        # total loss (must be a torch.Tensor)
+        # total loss (must be a torch.Tensor), and logs
         total_loss = sum(condition_losses)
+        self.save_logs_and_release()
         return total_loss.as_subclass(torch.Tensor)
 
     def loss_data(self, input_tensor, output_tensor):
@@ -205,7 +206,7 @@ class PINNInterface(SolverInterface, metaclass=ABCMeta):
         )
         self.__logged_res_losses.append(loss_value)
 
-    def on_train_epoch_end(self):
+    def save_logs_and_release(self):
         """
         At the end of each epoch we free the stored losses. This function
         should not be override if not intentionally.
@@ -218,7 +219,6 @@ class PINNInterface(SolverInterface, metaclass=ABCMeta):
             )
             # free the logged losses
             self.__logged_res_losses = []
-        return super().on_train_epoch_end()
 
     def _clamp_inverse_problem_params(self):
         """