docs: def _pseudodepths_wenner(configs, spacing=1, grid=None):
      """Given distances between electrodes, compute Wenner pseudo
      depths for the provided configuration
  
      The pseudodepth is computed after Roy & Apparao, 1971, as 0.11 times
      the distance between the two outermost electrodes. It's not really
      clear why the Wenner depths are different from the Dipole-Dipole
      depths, given the fact that Wenner configurations are a complete subset
      of the Dipole-Dipole configurations.
  
      """
      if grid is None:
          xpositions = (configs - 1) * spacing
      else:
          xpositions = grid.get_electrode_positions()[configs - 1, 0]
  
      z = np.abs(np.max(xpositions, axis=1) - np.min(xpositions, axis=1)) * -0.11
      x = np.mean(xpositions, axis=1)
      return x, z