title: PHPExcel - chart rendering and load excel giving error
body: <pre><code>require_once('PHPExcel-1.7.7/Classes/PHPExcel.php');
  
  $inputFileName = 'RN Tracker.xlsx';
  
  $inputFileType = PHPExcel_IOFactory::identify($inputFileName);
  
   $objReader = PHPExcel_IOFactory::createReader($inputFileType);
  </code></pre>
  
  <p>if i try following</p>
  
  <pre><code>$objReader-&gt;setIncludeCharts(TRUE);
  </code></pre>
  
  <p>during load i get following error message:</p>
  
  <pre><code>Warning: PHPExcel_Reader_Excel2007::load(): Node no longer exists in /users/pravkum4/html/tracker/PHPExcel-1.7.7/Classes/PHPExcel/Reader/Excel2007.php on line 1518
  
  Notice: Trying to get property of non-object in /users/pravkum4/html/tracker/PHPExcel-1.7.7/Classes/PHPExcel/Reader/Excel2007.php on line 1519
  
  Fatal error: Call to a member function children() on a non-object in /users/pravkum4/html/tracker/PHPExcel-1.7.7/Classes/PHPExcel/Reader/Excel2007.php on line 1519
  </code></pre>
  
  <p>What mistake i am doing here?
  Should i include some additional class for chart?</p>
  
  <p>Does chart option is included by default in load method of reader? chart count gives 0. :((
  Sometimes gives correct chart count but rendering doesn't work.</p>
  
  <p><img src="https://i.stack.imgur.com/wolNP.png" alt="enter image description here"></p>
  
  <p>One more thing, what is this code? not working for me. Sometimes i get jpgraph_pie.php missing.</p>
  
  <pre><code>PHPExcel_Settings::setChartRenderer(
      PHPExcel_Settings::CHART_RENDERER_JPGRAPH,
      dirname(__FILE__).'/../../libraries/Charts/jpgraph3.5.0b1/src'
  );
  </code></pre>
  
  <p>Please provide a tutorial for chart rendering. Thank you so much in Advance.</p>