docs: def plot_prof_2(self, mod, species, xlim1, xlim2):
  
          """
          Plot one species for cycle between xlim1 and xlim2
  
          Parameters
          ----------
          mod : string or integer
              Model to plot, same as cycle number.
          species : list
              Which species to plot.
          xlim1, xlim2 : float
              Mass coordinate range.
  
          """
  
          mass=self.se.get(mod,'mass')
          Xspecies=self.se.get(mod,'yps',species)
          pyl.plot(mass,Xspecies,'-',label=str(mod)+', '+species)
          pyl.xlim(xlim1,xlim2)
          pyl.legend()