def local_ij_delta_to_class(local_ij_delta):
    """
    :param local_ij_delta: tuple (i, j) returned from local_ij_delta
    :return: a value 0-5 for the each of the possible adjecent hexagons, or -1 if
             the (i,j) tuple is representing a non-adjecent hexagon coordinate
    """
    if (local_ij_delta == (0, 1)):
        return 0
    elif (local_ij_delta == (1, 0)):
        return 1
    elif (local_ij_delta == (0, -1)):
        return 2
    elif (local_ij_delta == (-1, 0)):
        return 3
    elif (local_ij_delta == (-1, -1)):
        return 4
    elif (local_ij_delta == (1, 1)):
        return 5
    else:
        return -1