docstr: Bin indices in a list according to their barycenter position
docstr_tok: ["Bin","indices","in","a","list","according","to","their","barycenter","position"]
code: def _barycenters_binning(self, barycenters):
      """Bin indices in a list according to their barycenter position"""
      in_bin = np.logical_and(
          np.all(barycenters >= self.min_box, axis=1),
          np.all(barycenters <= self.max_box, axis=1),
      )
  
      baryc_to_box = barycenters[in_bin] - self.min_box
      baryc_bins_id = (baryc_to_box // self.bin_size).astype(int)
      baryc_multiid = np.ravel_multi_index(
          baryc_bins_id.T, self.bin_shape
      )
  
      sort_id = np.argsort(baryc_multiid)
      u_bin, mapping = np.unique(
          baryc_multiid[sort_id], return_index=True
      )
      slines_ids = np.split(
          np.flatnonzero(in_bin)[sort_id], mapping[1:]
      )
      return u_bin, slines_ids
  
file_path: dipy/dipy/segment/fss.py
imports: import warnings
  import numpy
  from scipy.sparse import coo_matrix
  from scipy.spatial import cKDTree
  from dipy.tracking.streamline import set_number_of_points
  from dipy.segment.metric import mean_euclidean_distance
  from dipy.io.stateful_tractogram import StatefulTractogram
label_desc: Use image node_id 6 for calling the FastStreamlineSearch obj's underlying member method code with example usage: obj._barycenters_binning(barycenters) and returns: u_bin,  slines_ids