Fixed index issue for mesh selection during training.

ANN_Data_Generator.py

@@ -216,7 +216,7 @@ class TrainingDataGenerator:
 
             # Build mesh for random stencil of given length
             mesh = self._mesh_list[int(np.random.randint(
-                3, high=12, size=1))-5].random_stencil(stencil_length)
+                3, high=12, size=1))-3].random_stencil(stencil_length)
 
             # Induce adjustment to capture troubled cells
             adjustment = 0 if initial_condition.is_smooth() \