code: def plotER(self,*args,**kwargs):
          
          if kwargs.pop('normed',False):
              kwargs['d2']= 'ERnorm'
          else:
              kwargs['d2']= 'ER'
          return self.plot(*args,**kwargs)
docs: NAME:
             plotER
          PURPOSE:
             plot ER(.) along the orbit
          INPUT:
             bovy_plot.bovy_plot inputs
          OUTPUT:
             figure to output device
          HISTORY:
             2014-06-16 - Written - Bovy (IAS)