docs: def write_calibration(calib, f, loc):
      """Write calibration set to file"""
      for i, node in enumerate(
          [p + '_' + s for p in ['pos', 'dir'] for s in 'xyz']):
          h5loc = loc + '/' + node
          ca = f.get_node(h5loc)
          ca.append(calib[:, i])
  
      du = f.get_node(loc + '/du')
      du.append(calib[:, 7].astype('u1'))
  
      floor = f.get_node(loc + '/floor')
      floor.append(calib[:, 8].astype('u1'))
  
      t0 = f.get_node(loc + '/t0')
      t0.append(calib[:, 6])
  
      if loc == "/hits":
          time = f.get_node(loc + "/time")
          offset = len(time)
          chunk_size = len(calib)
          time[offset - chunk_size:offset] += calib[:, 6]