How to add to a Multidimensional Array?

PHP
2

They appear to be cell coordinates within an Excel spreadsheet.

<?php
$source = array(0,2 + $this->productSize*($progress['importedCount']));
//...
$product_name = strval($productSheetObj->getCell(PHPExcel_Cell::stringFromColumnIndex($source[0] + $map['name'][0]) . ($source[1] + $map['name'][1]))->getValue());