'Plot item'

def plot_item(self, funcname):

    index = self.currentIndex()
    if self.__prepare_plot():
        key = self.model.get_key(index)
        try:
            self.plot(key, funcname)
        except (ValueError, TypeError) as error:
            QMessageBox.critical(self, _('Plot'), (_('<b>Unable    to    plot    data.</b><br><br>Error    message:<br>%s') % str(error)))
