def pick_cell (self, x, y):
        try:
            self.cellpicker.pick(float(x), float(y), 0.0,
                                 self.renwin.renderer)
        except TypeError:
            # On old versions of VTK, the signature used to be different
            self.cellpicker.pick((float(x), float(y), 0.0),
                                 self.renwin.renderer)

        cp = self.cellpicker
        id = cp.cell_id
        picked_data = PickedData()
        coord = cp.pick_position
        picked_data.coordinate = coord

        if id > -1:
            data = cp.mapper.input.cell_data
            bounds = cp.mapper.input.bounds

            picked_data.valid = 1
            picked_data.cell_id = id
            picked_data.data = data

            self._update_actor(coord, bounds)
        else:
            self.p_actor.visibility = 0

        self.renwin.render()
        return picked_data
Picks the nearest cell. Returns a `PickedData` instance.
dataset/ETHPy150Open enthought/mayavi/tvtk/pyface/picker.py/Picker.pick_cell