public function imageDraw($externalData = NULL)
 {
     $this->_heading['text'] = 'Schülerteilnahmen in Schuljahren';
     $this->setMarginRatio(array('X' => 0.15, 'Y' => 0.15));
     $this->setScale(array("GridR" => 200, "GridG" => 200, "GridB" => 200, "DrawSubTicks" => TRUE, 'LabelRotation' => 45, "Pos" => SCALE_POS_TOPBOTTOM, "Mode" => SCALE_MODE_ADDALL_START0));
     parent::imageDraw();
 }
 public function imageDraw($externalData = NULL)
 {
     $this->_heading['text'] = 'Wahlen in Jahrgänge aufgeteilt';
     parent::imageDraw();
 }
 /**
  * Constructs the class
  */
 public function __construct($data)
 {
     $this->setPData($data);
     parent::__construct();
 }