code: def _display_value_vertical(self, value):
          
          if self._showvalue:
              self.label.configure(text=self._formatter.format(float(value)))
              if self._labelpos in ['e', 'w']:
                  y = self.convert_to_pixels(float(value))
                  self.label.place_configure(y=y)
docs: Display the current value and update the label position.