Chart Not Loaded in PHPExcel

Hi I have just loaded a xlsx file with graph,but the graph is not displayed in output.

This is my code :

 $objPHPExcel=$objPHPExcel_new = new PHPExcel();
$objReader = PHPExcel_IOFactory::createReader('Excel2007');
$objPHPExcel = $objReader->load("../Graph_sample.xlsx");



$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
$objWriter->save('result.xlsx');