PHPOffice/PHPExcel — pull request #435 by masanaikeshima (2014-09-10 14:50:06+00:00)
Title: Fixing Pie Chart example to display pie charts

I have noticed that this example is currently throwing the following error when opening the produced Excel Spreadsheet - "We found a problem with some content in .xlsx. Do you want us to try to recover as much as we can? If you trust the source of this workbook click Yes".

In order to fix this I have set the removed the PlotGrouping setting (currently PHPExcel_Chart_DataSeries::GROUPING_STANDARD) to NULL and it appears to work.