title: Adding an array formula to an Excel spreadsheet using PHP
body: <p>I'm generating an excel spreadsheet using the PEAR extension, Spreadsheet_Excel_Writer. I need to add an <a href="http://www.cpearson.com/excel/ArrayFormulas.aspx" rel="nofollow noreferrer">array formula</a> to one of the cells, but all the info I've read about them only discusses them as if you're in the Excel program itself: it says you have to type in the formula as normal and then press <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>Enter</kbd> to switch it to an array formula.</p>
  
  <p>Is there a way I can do this programmatically?</p>