docs: def bar_chart_mf(data, path_name):
      """Make a bar chart for data on MF quantities."""
      N = len(data)
  
      ind = np.arange(N)  # the x locations for the groups
      width = 0.8       # the width of the bars
  
      fig, ax = pyplot.subplots()
      rects1 = ax.bar(ind, data, width, color='g')
  
      # add some text for labels, title and axes ticks
      ax.set_ylabel('Population')
      ax.set_xticks(ind+width/2)
      labs = ['m='+str(i) for i in range(-N/2+1, N/2+1)]
      ax.set_xticklabels(labs)
  
      def autolabel(rects):
          # attach some text labels
          for rect in rects:
              rect.get_height()
  
      autolabel(rects1)
      pyplot.savefig(path_name)
      pyplot.close()