code: def theta2_purities_chart (self):
          
  
          # Specify the order of the different possible categories
          keys = OrderedDict()
          keys['proportion_germline'] =   { 'name': 'Germline' }
          keys['proportion_tumour_1'] =   { 'name': 'Tumour Subclone 1' }
          keys['proportion_tumour_2'] =   { 'name': 'Tumour Subclone 2' }
          keys['proportion_tumour_3'] =   { 'name': 'Tumour Subclone 3' }
          keys['proportion_tumour_4'] =   { 'name': 'Tumour Subclone 4' }
          keys['proportion_tumour_5'] =   { 'name': 'Tumour Subclone 5' }
          keys['proportion_tumour_gt5'] = { 'name': 'Tumour Subclones > 5' }
  
          # Config for the plot
          pconfig = {
              'id': 'theta2_purity_plot',
              'title': 'THetA2: Tumour Subclone Purities',
              'cpswitch': False,
              'ymin': 0,
              'ymax': 100,
              'ylab': '% Purity',
              'tt_suffix': '%'
          }
  
          return bargraph.plot(self.theta2_data, keys, pconfig)
docs: Make the plot showing alignment rates