code: def on_next_button(self, event):
          
          self.do_auto_save()
          self.selected_meas = []
          index = self.specimens.index(self.s)
          try:
              fit_index = self.pmag_results_data['specimens'][self.s].index(
                  self.current_fit)
          except KeyError:
              fit_index = None
          except ValueError:
              fit_index = None
          if index == len(self.specimens)-1:
              index = 0
          else:
              index += 1
          # sets self.s calculates params etc.
          self.initialize_CART_rot(str(self.specimens[index]))
          self.specimens_box.SetStringSelection(str(self.s))
          if fit_index != None and self.s in self.pmag_results_data['specimens']:
              try:
                  self.current_fit = self.pmag_results_data['specimens'][self.s][fit_index]
              except IndexError:
                  self.current_fit = None
          else:
              self.current_fit = None
          if self.ie_open:
              self.ie.change_selected(self.current_fit)
          self.update_selection()
docs: update figures and text when a next button is selected