diff --git a/.gitignore b/.gitignore
new file mode 100644
index 00000000..7d3ffccc
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+unitTests/codeCoverage
diff --git a/Classes/PHPExcel/Chart/DataSeriesValues.php b/Classes/PHPExcel/Chart/DataSeriesValues.php
index ea6c4925..90ef6687 100644
--- a/Classes/PHPExcel/Chart/DataSeriesValues.php
+++ b/Classes/PHPExcel/Chart/DataSeriesValues.php
@@ -36,6 +36,14 @@
 class PHPExcel_Chart_DataSeriesValues
 {
 
+	const DATASERIES_TYPE_STRING	= 'String';
+	const DATASERIES_TYPE_NUMBER	= 'Number';
+
+	private static $_dataTypeValues = array(
+		self::DATASERIES_TYPE_STRING,
+		self::DATASERIES_TYPE_NUMBER,
+	);
+
 	/**
 	 * Series Data Type
 	 *
@@ -81,9 +89,9 @@ class PHPExcel_Chart_DataSeriesValues
 	/**
 	 * Create a new PHPExcel_Chart_DataSeriesValues object
 	 */
-	public function __construct($dataType = null, $dataSource = null, $formatCode = null, $pointCount = 0, $dataValues = array(), $marker = null)
+	public function __construct($dataType = self::DATASERIES_TYPE_NUMBER, $dataSource = null, $formatCode = null, $pointCount = 0, $dataValues = array(), $marker = null)
 	{
-		$this->_dataType = $dataType;
+		$this->setDataType($dataType);
 		$this->_dataSource = $dataSource;
 		$this->_formatCode = $formatCode;
 		$this->_pointCount = $pointCount;
@@ -103,10 +111,18 @@ class PHPExcel_Chart_DataSeriesValues
 	/**
 	 * Set Series Data Type
 	 *
-	 * @param	string	$dataType
+	 * @param	string	$dataType	Datatype of this data series
+	 *								Typical values are:
+	 *									PHPExcel_Chart_DataSeriesValues::DATASERIES_TYPE_STRING
+	 *										Normally used for axis point values
+	 *									PHPExcel_Chart_DataSeriesValues::DATASERIES_TYPE_NUMBER
+	 *										Normally used for chart data values
 	 * @return	PHPExcel_Chart_DataSeriesValues
 	 */
-	public function setDataType($dataType = 'Number') {
+	public function setDataType($dataType = self::DATASERIES_TYPE_NUMBER) {
+		if (!in_array($dataType, self::$_dataTypeValues)) {
+    		throw new PHPExcel_Chart_Exception('Invalid datatype for chart data series values');
+		}
 		$this->_dataType = $dataType;
 
 		return $this;
diff --git a/Classes/PHPExcel/Chart/Exception.php b/Classes/PHPExcel/Chart/Exception.php
new file mode 100644
index 00000000..0c296ba1
--- /dev/null
+++ b/Classes/PHPExcel/Chart/Exception.php
@@ -0,0 +1,52 @@
+<?php
+/**
+ * PHPExcel
+ *
+ * Copyright (c) 2006 - 2012 PHPExcel
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * @category   PHPExcel
+ * @package    PHPExcel_Chart
+ * @copyright  Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
+ * @license	http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
+ * @version	##VERSION##, ##DATE##
+ */
+
+
+/**
+ * PHPExcel_Chart_Exception
+ *
+ * @category   PHPExcel
+ * @package    PHPExcel_Chart
+ * @copyright  Copyright (c) 2006 - 2012 PHPExcel (http://www.codeplex.com/PHPExcel)
+ */
+class PHPExcel_Chart_Exception extends Exception {
+	/**
+	 * Error handler callback
+	 *
+	 * @param mixed $code
+	 * @param mixed $string
+	 * @param mixed $file
+	 * @param mixed $line
+	 * @param mixed $context
+	 */
+	public static function errorHandlerCallback($code, $string, $file, $line, $context) {
+		$e = new self($string, $code);
+		$e->line = $line;
+		$e->file = $file;
+		throw $e;
+	}
+}
diff --git a/Classes/PHPExcel/Chart/Legend.php b/Classes/PHPExcel/Chart/Legend.php
index 5e914aae..80b54ff8 100644
--- a/Classes/PHPExcel/Chart/Legend.php
+++ b/Classes/PHPExcel/Chart/Legend.php
@@ -49,13 +49,13 @@ class PHPExcel_Chart_Legend
 	const POSITION_TOP		= 't';
 	const POSITION_TOPRIGHT	= 'tr';
 
-	private static $_positionXref = array( self::xlLegendPositionBottom	=> self::POSITION_BOTTOM,
-										   self::xlLegendPositionCorner	=> self::POSITION_TOPRIGHT,
-										   self::xlLegendPositionCustom	=> '??',
-										   self::xlLegendPositionLeft	=> self::POSITION_LEFT,
-										   self::xlLegendPositionRight	=> self::POSITION_RIGHT,
-										   self::xlLegendPositionTop	=> self::POSITION_TOP
-									     );
+	private static $_positionXLref = array( self::xlLegendPositionBottom	=> self::POSITION_BOTTOM,
+											self::xlLegendPositionCorner	=> self::POSITION_TOPRIGHT,
+											self::xlLegendPositionCustom	=> '??',
+											self::xlLegendPositionLeft		=> self::POSITION_LEFT,
+											self::xlLegendPositionRight		=> self::POSITION_RIGHT,
+											self::xlLegendPositionTop		=> self::POSITION_TOP
+										  );
 
 	/**
 	 * Legend position
@@ -69,24 +69,24 @@ class PHPExcel_Chart_Legend
 	 *
 	 * @var	boolean
 	 */
-	private $_overlay = true;
+	private $_overlay = TRUE;
 
 	/**
 	 * Legend Layout
 	 *
 	 * @var	PHPExcel_Chart_Layout
 	 */
-	private $_layout = null;
+	private $_layout = NULL;
 
 
 	/**
 	 *	Create a new PHPExcel_Chart_Legend
 	 */
-	public function __construct($position = null, PHPExcel_Chart_Layout $layout = null, $overlay= false)
+	public function __construct($position = self::POSITION_RIGHT, PHPExcel_Chart_Layout $layout = NULL, $overlay = FALSE)
 	{
-		$this->_position = $position;
+		$this->setPosition($position);
 		$this->_layout = $layout;
-		$this->_overlay = $overlay;
+		$this->setOverlay($overlay);
 	}
 
 	/**
@@ -104,12 +104,11 @@ class PHPExcel_Chart_Legend
 	 * @param	string	$position
 	 */
 	public function setPosition($position = self::POSITION_RIGHT) {
-		if (!in_array($position,self::$positionXref)) {
+		if (!in_array($position,self::$_positionXLref)) {
 			return false;
 		}
 
 		$this->_position = $position;
-
 		return true;
 	}
 
@@ -119,7 +118,7 @@ class PHPExcel_Chart_Legend
 	 * @return	number
 	 */
 	public function getPositionXL() {
-		return array_search($this->_position,self::$positionXref);
+		return array_search($this->_position,self::$_positionXLref);
 	}
 
 	/**
@@ -128,11 +127,11 @@ class PHPExcel_Chart_Legend
 	 * @param	number	$positionXL
 	 */
 	public function setPositionXL($positionXL = self::xlLegendPositionRight) {
-		if (!array_key_exists($positionXL,self::$positionXref)) {
+		if (!array_key_exists($positionXL,self::$_positionXLref)) {
 			return false;
 		}
 
-		$this->_position = self::$positionXref[$positionXL];
+		$this->_position = self::$_positionXLref[$positionXL];
 		return true;
 	}
 
@@ -148,10 +147,16 @@ class PHPExcel_Chart_Legend
 	/**
 	 * Set allow overlay of other elements?
 	 *
-	 * @param	boolean	$value
+	 * @param	boolean	$overlay
+	 * @return	boolean
 	 */
-	public function setOverlay($value=false) {
-		$this->_overlay = $value;
+	public function setOverlay($overlay = FALSE) {
+		if (!is_bool($overlay)) {
+			return false;
+		}
+
+		$this->_overlay = $overlay;
+		return true;
 	}
 
 	/**
diff --git a/Tests/26utf8.php b/Tests/26utf8.php
index 41e85af2..b2e69ec0 100644
--- a/Tests/26utf8.php
+++ b/Tests/26utf8.php
@@ -34,6 +34,17 @@ date_default_timezone_set('Europe/London');
 require_once '../Classes/PHPExcel.php';
 
 
+//	Change these values to select the PDF Rendering library that you wish to use
+//		and its directory location on your server
+//$rendererName = PHPExcel_Settings::PDF_RENDERER_TCPDF;
+$rendererName = PHPExcel_Settings::PDF_RENDERER_MPDF;
+//$rendererName = PHPExcel_Settings::PDF_RENDERER_DOMPDF;
+//$rendererLibrary = 'tcPDF5.9';
+$rendererLibrary = 'mPDF5.4';
+//$rendererLibrary = 'domPDF0.6.0beta3';
+$rendererLibraryPath = dirname(__FILE__).'/../../../libraries/PDF/' . $rendererLibrary;
+
+
 // Read from Excel2007 (.xlsx) template
 echo date('H:i:s') , " Load Excel2007 template file" , PHP_EOL;
 $objReader = PHPExcel_IOFactory::createReader('Excel2007');
@@ -61,9 +72,24 @@ echo date('H:i:s') , " File written to " , str_replace('.php', '.htm', __FILE__)
 
 // Export to PDF (.pdf)
 echo date('H:i:s') , " Write to PDF format" , PHP_EOL;
-$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'PDF');
-$objWriter->save(str_replace('.php', '.pdf', __FILE__));
-echo date('H:i:s') , " File written to " , str_replace('.php', '.pdf', __FILE__) , PHP_EOL;
+try {
+	if (!PHPExcel_Settings::setPdfRenderer(
+		$rendererName,
+		$rendererLibraryPath
+	)) {
+		echo (
+			'NOTICE: Please set the $rendererName and $rendererLibraryPath values' .
+			PHP_EOL .
+			'at the top of this script as appropriate for your directory structure'
+		);
+	} else {
+		$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'PDF');
+		$objWriter->save(str_replace('.php', '.pdf', __FILE__));
+		echo date('H:i:s') , " File written to " , str_replace('.php', '.pdf', __FILE__) , PHP_EOL;
+	}
+} catch (Exception $e) {
+	echo date('H:i:s') , ' EXCEPTION: ', $e->getMessage() , PHP_EOL;
+}
 
 // Remove first two rows with field headers before exporting to CSV
 echo date('H:i:s') , " Removing first two heading rows for CSV export" , PHP_EOL;
diff --git a/Tests/33chartcreate.php b/Tests/33chartcreate.php
index 978b9102..f688b01c 100644
--- a/Tests/33chartcreate.php
+++ b/Tests/33chartcreate.php
@@ -49,18 +49,18 @@ $objWorksheet->fromArray(
 	)
 );
 
-//	Set the Labels for each dataset we want to plot
-$labels = array(
+//	Set the Labels for each data series we want to plot
+$dataseriesLabels = array(
 	new PHPExcel_Chart_DataSeriesValues('String', 'Worksheet!$B$1', null, 1),	//	2010
 	new PHPExcel_Chart_DataSeriesValues('String', 'Worksheet!$C$1', null, 1),	//	2011
 	new PHPExcel_Chart_DataSeriesValues('String', 'Worksheet!$D$1', null, 1),	//	2012
 );
 //	Set the X-Axis Labels
-$categories = array(
+$xAxisTickValues = array(
 	new PHPExcel_Chart_DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4),	//	Q1 to Q4
 );
-//	Set the Data values for each dataset we want to plot
-$values = array(
+//	Set the Data values for each data series we want to plot
+$dataSeriesValues = array(
 	new PHPExcel_Chart_DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
 	new PHPExcel_Chart_DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
 	new PHPExcel_Chart_DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
@@ -70,10 +70,10 @@ $values = array(
 $series = new PHPExcel_Chart_DataSeries(
 	PHPExcel_Chart_DataSeries::TYPE_BARCHART,		// plotType
 	PHPExcel_Chart_DataSeries::GROUPING_CLUSTERED,	// plotGrouping
-	array(0, 1, 2),									// plotOrder
-	$labels,										// plotLabel
-	$categories,									// plotCategory
-	$values											// plotValues
+	range(0, count($dataSeriesValues)-1),			// plotOrder
+	$dataseriesLabels,								// plotLabel
+	$xAxisTickValues,								// plotCategory
+	$dataSeriesValues								// plotValues
 );
 //	Set additional dataseries parameters
 $series->setPlotDirection(PHPExcel_Chart_DataSeries::DIRECTION_COL);
@@ -84,6 +84,7 @@ $plotarea = new PHPExcel_Chart_PlotArea(null, array($series));
 $legend = new PHPExcel_Chart_Legend(PHPExcel_Chart_Legend::POSITION_RIGHT, null, false);
 
 $title = new PHPExcel_Chart_Title('Test Chart');
+$yAxisLabel = new PHPExcel_Chart_Title('Value ($k)');
 
 
 //	Create the chart
@@ -95,7 +96,7 @@ $chart = new PHPExcel_Chart(
 	true,			// plotVisibleOnly
 	0,				// displayBlanksAs
 	null,			// xAxisLabel
-	null			// yAxisLabel
+	$yAxisLabel		// yAxisLabel
 );
 
 //	Set the position where the chart should appear in the worksheet
diff --git a/unitTests/PHPExcel/Chart/DataSeriesValuesTest.php b/unitTests/PHPExcel/Chart/DataSeriesValuesTest.php
new file mode 100644
index 00000000..38284de9
--- /dev/null
+++ b/unitTests/PHPExcel/Chart/DataSeriesValuesTest.php
@@ -0,0 +1,55 @@
+<?php
+
+
+class DataSeriesValuesTest extends PHPUnit_Framework_TestCase
+{
+
+    public function setUp()
+    {
+        if (!defined('PHPEXCEL_ROOT'))
+        {
+            define('PHPEXCEL_ROOT', APPLICATION_PATH . '/');
+        }
+        require_once(PHPEXCEL_ROOT . 'PHPExcel/Autoloader.php');
+	}
+
+	public function testSetDataType()
+	{
+		$dataTypeValues = array(
+			'Number',
+			'String'
+		);
+
+		$testInstance = new PHPExcel_Chart_DataSeriesValues;
+
+		foreach($dataTypeValues as $dataTypeValue) {
+			$result = $testInstance->setDataType($dataTypeValue);
+			$this->assertTrue($result instanceof PHPExcel_Chart_DataSeriesValues);
+		}
+	}
+
+	public function testSetInvalidDataTypeThrowsException()
+	{
+		$testInstance = new PHPExcel_Chart_DataSeriesValues;
+
+		try {
+			$result = $testInstance->setDataType('BOOLEAN');
+		} catch (Exception $e) {
+			$this->assertEquals($e->getMessage(), 'Invalid datatype for chart data series values');
+			return;
+		}
+		$this->fail('An expected exception has not been raised.');
+	}
+
+	public function testGetDataType()
+	{
+		$dataTypeValue = 'String';
+
+		$testInstance = new PHPExcel_Chart_DataSeriesValues;
+		$setValue = $testInstance->setDataType($dataTypeValue);
+
+		$result = $testInstance->getDataType();
+		$this->assertEquals($dataTypeValue,$result);
+	}
+
+}
diff --git a/unitTests/PHPExcel/Chart/LayoutTest.php b/unitTests/PHPExcel/Chart/LayoutTest.php
new file mode 100644
index 00000000..f24e01c3
--- /dev/null
+++ b/unitTests/PHPExcel/Chart/LayoutTest.php
@@ -0,0 +1,37 @@
+<?php
+
+
+class LayoutTest extends PHPUnit_Framework_TestCase
+{
+
+    public function setUp()
+    {
+        if (!defined('PHPEXCEL_ROOT'))
+        {
+            define('PHPEXCEL_ROOT', APPLICATION_PATH . '/');
+        }
+        require_once(PHPEXCEL_ROOT . 'PHPExcel/Autoloader.php');
+	}
+
+	public function testSetLayoutTarget()
+	{
+		$LayoutTargetValue = 'String';
+
+		$testInstance = new PHPExcel_Chart_Layout;
+
+		$result = $testInstance->setLayoutTarget($LayoutTargetValue);
+		$this->assertTrue($result instanceof PHPExcel_Chart_Layout);
+	}
+
+	public function testGetLayoutTarget()
+	{
+		$LayoutTargetValue = 'String';
+
+		$testInstance = new PHPExcel_Chart_Layout;
+		$setValue = $testInstance->setLayoutTarget($LayoutTargetValue);
+
+		$result = $testInstance->getLayoutTarget();
+		$this->assertEquals($LayoutTargetValue,$result);
+	}
+
+}
diff --git a/unitTests/PHPExcel/Chart/LegendTest.php b/unitTests/PHPExcel/Chart/LegendTest.php
new file mode 100644
index 00000000..4c4f8df8
--- /dev/null
+++ b/unitTests/PHPExcel/Chart/LegendTest.php
@@ -0,0 +1,134 @@
+<?php
+
+
+class LegendTest extends PHPUnit_Framework_TestCase
+{
+
+    public function setUp()
+    {
+        if (!defined('PHPEXCEL_ROOT'))
+        {
+            define('PHPEXCEL_ROOT', APPLICATION_PATH . '/');
+        }
+        require_once(PHPEXCEL_ROOT . 'PHPExcel/Autoloader.php');
+	}
+
+	public function testSetPosition()
+	{
+		$positionValues = array(
+			PHPExcel_Chart_Legend::POSITION_RIGHT,
+			PHPExcel_Chart_Legend::POSITION_LEFT,
+			PHPExcel_Chart_Legend::POSITION_TOP,
+			PHPExcel_Chart_Legend::POSITION_BOTTOM,
+			PHPExcel_Chart_Legend::POSITION_TOPRIGHT,
+		);
+
+		$testInstance = new PHPExcel_Chart_Legend;
+
+		foreach($positionValues as $positionValue) {
+			$result = $testInstance->setPosition($positionValue);
+			$this->assertTrue($result);
+		}
+	}
+
+	public function testSetInvalidPositionReturnsFalse()
+	{
+		$testInstance = new PHPExcel_Chart_Legend;
+
+		$result = $testInstance->setPosition('BottomLeft');
+		$this->assertFalse($result);
+		//	Ensure that value is unchanged
+		$result = $testInstance->getPosition();
+		$this->assertEquals(PHPExcel_Chart_Legend::POSITION_RIGHT,$result);
+	}
+
+	public function testGetPosition()
+	{
+		$PositionValue = PHPExcel_Chart_Legend::POSITION_BOTTOM;
+
+		$testInstance = new PHPExcel_Chart_Legend;
+		$setValue = $testInstance->setPosition($PositionValue);
+
+		$result = $testInstance->getPosition();
+		$this->assertEquals($PositionValue,$result);
+	}
+
+	public function testSetPositionXL()
+	{
+		$positionValues = array(
+			PHPExcel_Chart_Legend::xlLegendPositionBottom,
+			PHPExcel_Chart_Legend::xlLegendPositionCorner,
+			PHPExcel_Chart_Legend::xlLegendPositionCustom,
+			PHPExcel_Chart_Legend::xlLegendPositionLeft,
+			PHPExcel_Chart_Legend::xlLegendPositionRight,
+			PHPExcel_Chart_Legend::xlLegendPositionTop,
+		);
+
+		$testInstance = new PHPExcel_Chart_Legend;
+
+		foreach($positionValues as $positionValue) {
+			$result = $testInstance->setPositionXL($positionValue);
+			$this->assertTrue($result);
+		}
+	}
+
+	public function testSetInvalidXLPositionReturnsFalse()
+	{
+		$testInstance = new PHPExcel_Chart_Legend;
+
+		$result = $testInstance->setPositionXL(999);
+		$this->assertFalse($result);
+		//	Ensure that value is unchanged
+		$result = $testInstance->getPositionXL();
+		$this->assertEquals(PHPExcel_Chart_Legend::xlLegendPositionRight,$result);
+	}
+
+	public function testGetPositionXL()
+	{
+		$PositionValue = PHPExcel_Chart_Legend::xlLegendPositionCorner;
+
+		$testInstance = new PHPExcel_Chart_Legend;
+		$setValue = $testInstance->setPositionXL($PositionValue);
+
+		$result = $testInstance->getPositionXL();
+		$this->assertEquals($PositionValue,$result);
+	}
+
+	public function testSetOverlay()
+	{
+		$overlayValues = array(
+			TRUE,
+			FALSE,
+		);
+
+		$testInstance = new PHPExcel_Chart_Legend;
+
+		foreach($overlayValues as $overlayValue) {
+			$result = $testInstance->setOverlay($overlayValue);
+			$this->assertTrue($result);
+		}
+	}
+
+	public function testSetInvalidOverlayReturnsFalse()
+	{
+		$testInstance = new PHPExcel_Chart_Legend;
+
+		$result = $testInstance->setOverlay('INVALID');
+		$this->assertFalse($result);
+
+		$result = $testInstance->getOverlay();
+		$this->assertFalse($result);
+	}
+
+	public function testGetOverlay()
+	{
+		$OverlayValue = TRUE;
+
+		$testInstance = new PHPExcel_Chart_Legend;
+		$setValue = $testInstance->setOverlay($OverlayValue);
+
+		$result = $testInstance->getOverlay();
+		$this->assertEquals($OverlayValue,$result);
+	}
+
+}