@staticmethod
def _tile_slice(ipix, tile_width, n_tiles_in_row):
    """Compute the 2-dim slice in the allsky ``data`` for a given tile."""
    w = tile_width
    row_idx, col_idx = divmod(ipix, n_tiles_in_row)
    return [slice(row_idx * w, (row_idx + 1) * w), slice(col_idx * w, (
        col_idx + 1) * w)]
