docs: def cmap_center_adjust(cmap, center_ratio):
      """
      Returns a new colormap based on the one given
      but adjusted so that the old center point higher
      (>0.5) or lower (<0.5)
  
      :param cmap: colormap instance (e.g., cm.jet)
      :param center_ratio:
  
      """
      if not (0. < center_ratio) & (center_ratio < 1.):
          return cmap
      a = math.log(center_ratio) / math.log(0.5)
      return cmap_powerlaw_adjust(cmap, a)