def plot4_nolog(self, num):
        """
           Plots the abundances of H-1, He-4, C-12 and O-16.
        """
        self.plot_prof_2(num,'H-1',0.,5.)
        self.plot_prof_2(num,'He-4',0.,5.)
        self.plot_prof_2(num,'C-12',0.,5.)
        self.plot_prof_2(num,'O-16',0.,5.)
        pyl.legend(loc=3)