PHP에서 엑셀을 CSV로 변환하는 방법

$filename = "myexcel.xlsx";
$objReader = PHPExcel_IOFactory::createReader('Excel2007');
$objPHPExcel = $objReader->load($filename);
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'CSV');
$objWriter->save(str_replace('.xlsx', '.csv',$filename));

统计
111213
212223
=A1+A222SUM(A3:A4)
php 输出excel 代码<？phpheader("Content-type:application/vnd.ms-excel");header("Content-Disposition:filename=excel.xls");echo "A1\t B1\t C1\n";echo "A2\t B2\t C2\n";echo "A3\t B3\t c3\n"；？>利用\t来区分单元格利用\n来换行。