added amp level option

pytorch_lightning/models/trainer.py

@@ -372,7 +372,8 @@ class Trainer(TrainerIO):
         if self.use_amp:
             for optimizer in self.optimizers:
                 with amp.scale_loss(loss, optimizer) as scaled_loss:
-                    scaled_loss.backward()
+                    optimizer.backward(scaled_loss)
+                    # scaled_loss.backward()
         else:
             loss.backward()
 

setup.py

@@ -7,7 +7,7 @@ from setuptools import setup, find_packages
 # http://blog.ionelmc.ro/2014/05/25/python-packaging/
 setup(
     name="pytorch-lightning",
-    version='0.1.dev1826',
+    version='0.1.dev1827',
     description="The Keras for ML researchers using PyTorch",
     author="William Falcon",
     author_email="waf2107@columbia.edu",