clean up flatten in tutorials, make neurochem trainer support aev caching (#92)

examples/cache_aev.py

@@ -92,15 +92,10 @@ else:
     torch.save(nn.state_dict(), model_checkpoint)
 
 
-class Flatten(torch.nn.Module):
-    def forward(self, x):
-        return x[0], x[1].flatten()
-
-
 ###############################################################################
 # Except that at here we do not include aev computer into our pipeline, because
 # the cache loader will load computed AEVs from disk.
-model = torch.nn.Sequential(nn, Flatten()).to(device)
+model = nn.to(device)
 
 ###############################################################################
 # This part is also a line by line copy

examples/nnp_training.py

@@ -95,19 +95,7 @@ if os.path.isfile(model_checkpoint):
 else:
     torch.save(nn.state_dict(), model_checkpoint)
 
-
-###############################################################################
-# The output energy tensor has shape ``(N, 1)`` where ``N`` is the number of
-# different structures in each minibatch. However, in the dataset, the label
-# has shape ``(N,)``. To make it possible to subtract these two tensors, we
-# need to flatten the output tensor.
-class Flatten(torch.nn.Module):
-    def forward(self, x):
-        return x[0], x[1].flatten()
-
-
-model = torch.nn.Sequential(aev_computer, nn, Flatten()).to(device)
-
+model = torch.nn.Sequential(aev_computer, nn).to(device)
 
 ###############################################################################
 # Now setup tensorboardX.

torchani/neurochem/__init__.py

@@ -304,6 +304,7 @@ def hartree2kcal(x):
 
 
 from ..data import BatchedANIDataset  # noqa: E402
+from ..data import AEVCacheLoader  # noqa: E402
 
 
 class Trainer:
@@ -315,12 +316,14 @@ class Trainer:
         tqdm (bool): whether to enable tqdm
         tensorboard (str): Directory to store tensorboard log file, set to\
             ``None`` to disable tensorboardX.
+        aev_caching (bool): Whether to use AEV caching.
     """
 
     def __init__(self, filename, device=torch.device('cuda'),
-                 tqdm=False, tensorboard=None):
+                 tqdm=False, tensorboard=None, aev_caching=False):
         self.filename = filename
         self.device = device
+        self.aev_caching = aev_caching
         if tqdm:
             import tqdm
             self.tqdm = tqdm.tqdm
@@ -528,6 +531,9 @@ class Trainer:
                 i = o
             atomic_nets[atom_type] = torch.nn.Sequential(*modules)
         self.model = ANIModel([atomic_nets[s] for s in self.consts.species])
+        if self.aev_caching:
+            self.nnp = self.model
+        else:
             self.nnp = torch.nn.Sequential(self.aev_computer, self.model)
         self.container = Container({'energies': self.nnp}).to(self.device)
 
@@ -561,7 +567,15 @@ class Trainer:
         return hartree2kcal(metrics['RMSE']), hartree2kcal(metrics['MAE'])
 
     def load_data(self, training_path, validation_path):
-        """Load training and validation dataset from file"""
+        """Load training and validation dataset from file.
+
+        If AEV caching is enabled, then the arguments are path to the cache
+        directory, otherwise it should be path to the dataset.
+        """
+        if self.aev_caching:
+            self.training_set = AEVCacheLoader(training_path)
+            self.validation_set = AEVCacheLoader(validation_path)
+        else:
             self.training_set = BatchedANIDataset(
                 training_path, self.consts.species_to_tensor,
                 self.training_batch_size, device=self.device,