def find_particles_in_tile(positions, tile):
bools = tile.contains(positions)<EOL>return np.arange(bools.size)[bools]<EOL>
Finds the particles in a tile, as numpy.ndarray of ints.

Parameters
----------
    positions : `numpy.ndarray`
        [N,3] array of the particle positions to check in the tile
    tile : :class:`peri.util.Tile` instance
        Tile of the region inside which to check for particles.

Returns
-------
    numpy.ndarray, int
        The indices of the particles in the tile.