docs: def serialize(pca, **kwargs):
      """
      Serialize an orientation object to a dict suitable
      for JSON
      """
      strike, dip, rake = pca.strike_dip_rake()
      hyp_axes = sampling_axes(pca)
  
      return dict(
          **kwargs,
          principal_axes = pca.axes.tolist(),
          hyperbolic_axes = hyp_axes.tolist(),
          n_samples = pca.n,
          strike=strike, dip=dip, rake=rake,
          angular_errors=[2*N.degrees(i)
              for i in angular_errors(hyp_axes)])