Return the indices into the lattice list attribute of elements whose Dynac
        type matches the input string.  Multiple input strings can be given, either
        as a comma-separated list or as a genuine Python list.

def get_x_inds(self, *dynac_type):
        """
        Return the indices into the lattice list attribute of elements whose Dynac
        type matches the input string.  Multiple input strings can be given, either
        as a comma-separated list or as a genuine Python list.
        """
        return [i for i, x in enumerate(self.lattice) for y in dynac_type if dynac_from_ele(x) == y]