code: def calculate_high_levels_data(self):
          
          high_level_type = str(self.level_box.GetValue())
          if high_level_type == 'sample':
              high_level_type = 'samples'
          if high_level_type == 'site':
              high_level_type = 'sites'
          if high_level_type == 'location':
              high_level_type = 'locations'
          high_level_name = str(self.level_names.GetValue())
          calculation_type = str(self.mean_type_box.GetValue())
          elements_type = self.UPPER_LEVEL_SHOW
          if self.ie_open:
              self.ie.mean_type_box.SetStringSelection(calculation_type)
          self.calculate_high_level_mean(
              high_level_type, high_level_name, calculation_type, elements_type, self.mean_fit)
docs: calculates high level mean data for the high level mean plot using
          information in level_box, level_names, mean_type_box, and
          mean_fit_box also updates the information in the ie to match high
          level mean data in main GUI.