fixed optimizer variable name in 15_transer_learning

Author: patrickloeber

15_transfer_learning.py

@@ -153,7 +153,7 @@ def train_model(model, criterion, optimizer, scheduler, num_epochs=25):
 #     validate(...)
 #     scheduler.step()
 
-step_lr_scheduler = lr_scheduler.StepLR(optimizer_ft, step_size=7, gamma=0.1)
+step_lr_scheduler = lr_scheduler.StepLR(optimizer, step_size=7, gamma=0.1)
 
 model = train_model(model, criterion, optimizer, step_lr_scheduler, num_epochs=25)