$chart5->add_series($sales);
$chart5->add_series($expenses);
$chart5->set_labels($labels);
$chart6 = new \core\chart_bar();
$chart6->set_title('HORIZONTAL BAR CHART');
$chart6->set_horizontal(true);
$chart6->add_series($sales);
$chart6->add_series($expenses);
$chart6->set_labels($labels);
$chart7 = new \core\chart_bar();
$chart7->set_title('STACKED BAR CHART');
$chart7->set_stacked(true);
$chart7->add_series($sales);
$chart7->add_series($expenses);
$chart7->set_labels($labels);
$chart8 = new \core\chart_bar();
$chart8->set_title('BAR CHART COMBINED WITH LINE CHART');
$expensesline = new \core\chart_series('Expenses', [400, 460, 1120, 540]);
$expensesline->set_type(\core\chart_series::TYPE_LINE);
$chart8->add_series($expensesline);
$chart8->add_series($sales);
$chart8->set_labels($labels);
echo $OUTPUT->render($chart);
echo $OUTPUT->render($chart2);
echo $OUTPUT->render($chart3);
echo $OUTPUT->render($chart4);
echo $OUTPUT->render($chart5);
echo $OUTPUT->render($chart6);
echo $OUTPUT->render($chart7);
echo $OUTPUT->render($chart8);
echo $OUTPUT->footer();
