docs: def energy_profile(self,ixaxis):
          """
              Plot radial profile of key energy generations eps_nuc,
              eps_neu etc.
  
              Parameters
              ----------
              ixaxis : 'mass' or 'radius'
          """
  
          mass = self.get('mass')
          radius = self.get('radius') * ast.rsun_cm
          eps_nuc = self.get('eps_nuc')
          eps_neu = self.get('non_nuc_neu')
  
          if ixaxis == 'mass':
              xaxis = mass
              xlab = 'Mass / M$_\odot$'
          else:
              xaxis = old_div(radius, 1.e8) # Mm
              xlab = 'Radius (Mm)'
  
          pl.plot(xaxis, np.log10(eps_nuc),
                  'k-',
                  label='$\epsilon_\mathrm{nuc}>0$')
          pl.plot(xaxis, np.log10(-eps_nuc),
                  'k--',
                  label='$\epsilon_\mathrm{nuc}<0$')
          pl.plot(xaxis, np.log10(eps_neu),
                  'r-',
                  label='$\epsilon_\\nu$')
  
          pl.xlabel(xlab)
          pl.ylabel('$\log(\epsilon_\mathrm{nuc},\epsilon_\\nu)$')
          pl.legend(loc='best').draw_frame(False)