Converts cell identifiers back to cell center coordinates.
This is the inverse of hexify_lonlat_to_cell.
See also
cell_to_lonlat for the recommended S4 interface,
hexify_lonlat_to_cell for the forward operation
Other coordinate conversion:
hexify_cell_id_to_quad_ij(),
hexify_cell_to_icosa_tri(),
hexify_cell_to_plane(),
hexify_cell_to_quad_ij(),
hexify_cell_to_quad_xy(),
hexify_grid_cell_to_lonlat(),
hexify_grid_to_cell(),
hexify_icosa_tri_to_plane(),
hexify_icosa_tri_to_quad_ij(),
hexify_icosa_tri_to_quad_xy(),
hexify_lonlat_to_cell(),
hexify_lonlat_to_plane(),
hexify_lonlat_to_quad_ij(),
hexify_quad_ij_to_cell(),
hexify_quad_ij_to_icosa_tri(),
hexify_quad_ij_to_xy(),
hexify_quad_xy_to_cell(),
hexify_quad_xy_to_icosa_tri(),
hexify_roundtrip_test()