docs: def _read_iso_abund_marco(self, mass_range, cycle):
          """
          plot the abundance of all the chemical species
  
          Parameters
          ----------
          mass_range : list
              A 1x2 array containing the lower and upper mass range.  If
              None, it will plot over the entire range.
          cycle : string or integer
              A string/integer of the cycle of interest.
  
          """
  
          import nuutils as u
  
          masses = []
          #    Check the inputs
          #if not self.se.cycles.count(str(cycle)):
          #    print 'You entered an cycle that doesn\'t exist in this dataset:', cycle
          #    print 'I will try and correct your format.'
          #    cyc_len = len(self.se.cycles[-1])
  
          #    print cyc_len, len(str(cycle))
          #
          #    while len(str(cycle)) < cyc_len:
          #        cycle = '0'+str(cycle)
          #        print cycle
  
          #    if not self.se.cycles.count(str(cycle)):
          #        print 'I was unable to correct your cycle.  Please check that it exists in your dataset.'
  
          masses = self.se.get(cycle,'mass')
          if mass_range == None:
              print('Using default mass range')
              mass_range = [min(masses),max(masses)]
          # what this was for??? Marco
          #masses.sort()
          #mass_range.sort()
  
  
  
          print('Using The following conditions:')
          print('\tmass_range:', mass_range[0], mass_range[1])
          print('\tcycle:', cycle)
  
          isotope_names = self.se.isotopes
          u.convert_specie_naming_from_h5_to_ppn(isotope_names)
          names_ppn_world = u.spe
          number_names_ppn_world = u.n_array
          u.define_zip_index_for_species(names_ppn_world,number_names_ppn_world)
  
          # from here below I read the abundance.
  
          #name_specie_in_file=self.se.dcols[5]
          # I am using directly 'iso_massf' only because somehow m20 explosive do not have dcols....
          name_specie_in_file='iso_massf'
          abunds=self.se.get(cycle,name_specie_in_file)
  
          global used_masses
          used_masses = []
          self.mass_frac = []
          for i in range(len(masses)):
              if mass_range[0] <=  masses[i]  and mass_range[1] >=  masses[i] :
                  used_masses.append(masses[i])
                  self.mass_frac.append(abunds[i])