FIX: `cube_out` and `cube_der` were not set
This caused an error when using 4D cubes with `full_output=True` and `mode="fullfr"`.
@@ -218,6 +218,9 @@ def median_sub(cube, angle_list, scale_list=None, fwhm=4, radius_int=0, asize=4,
if verbose:
timing(start_time)
+ cube_out = None
+ cube_der = None
+
elif mode == 'annular':
if verbose:
print('N annuli = {}, mean FWHM = {:.3f}'.format(n_annuli,
