Fixes an important bug where recursion in np.gradient() dropped an ar…

…gument

aerosandbox/numpy/calculus.py

@@ -3,6 +3,7 @@
 from aerosandbox.numpy.determine_type import is_casadi_type
 from aerosandbox.numpy.arithmetic_dyadic import centered_mod as _centered_mod
 from aerosandbox.numpy.array import array, concatenate, reshape
+from typing import Tuple
 
 
 def diff(a, n=1, axis=-1, period=None):
@@ -134,7 +135,9 @@ def gradient(
                     f,
                     varargs[axis_i],
                     axis=axis_i,
-                    edge_order=edge_order
+                    edge_order=edge_order,
+                    n=n,
+                    period=period,
                 )
                 for axis_i in axis
             ]
@@ -152,7 +155,7 @@ def gradient(
             dx_shape[axis] = shape[axis] - 1
             dx = reshape(dx, dx_shape)
 
-            def get_slice(slice_obj: slice):
+            def get_slice(slice_obj: slice) -> Tuple[slice]:
                 slices = [slice(None)] * len(shape)
                 slices[axis] = slice_obj
                 return tuple(slices)