Corr3dMM: add docs

theano/tensor/nnet/corr3d.py

@@ -40,6 +40,8 @@ class BaseCorr3dMM(gof.OpenMPOp):
         Perform subsampling of the output (default: (1, 1, 1)).
     filter_dilation
         Perform dilated correlation (default: (1, 1, 1))
+    num_groups
+        Perform grouped convolutions (default: 1)
     """
     check_broadcast = False
     __props__ = ('border_mode', 'subsample', 'filter_dilation', 'num_groups')
@@ -559,7 +561,8 @@ class Corr3dMM(BaseCorr3dMM):
         The filter dilation operation applied to each input image.
         Should be a tuple with 3 elements.
         Set to `(1, 1, 1)` to disable filter dilation.
-
+    num_groups
+        Perform grouped convolutions (default: 1)
     """
 
     _direction = "forward"