docs: def _scale_prof(step, rprof, rad=None):
      """Scale profile to take sphericity into account"""
      rbot, rtop = misc.get_rbounds(step)
      if rbot == 0:  # not spherical
          return rprof
      if rad is None:
          rad = step.rprof['r'].values + rbot
      return rprof * (2 * rad / (rtop + rbot))**2