  Affine Grassmann codes are a variant of generalized Reed-Muller codes and are
closely related to Grassmann codes. These codes were introduced in a recent
work [2]. Here we consider, more generally, affine Grassmann codes of a given
level. We explicitly determine the dual of an affine Grassmann code of any
level and compute its minimum distance. Further, we ameliorate the results of
[2] concerning the automorphism group of affine Grassmann codes. Finally, we
prove that affine Grassmann codes and their duals have the property that they
are linear codes generated by their minimum-weight codewords. This provides a
clean analogue of a corresponding result for generalized Reed-Muller codes.
