             setNeedsDisplay()
         }
     }
+    
+    /// The max angle that is used for calculating the pie-circle.
+    /// 360 means it's a full pie-chart, 180 results in a half-pie-chart.
+    /// - default: 360.0
+    public var maxAngle: CGFloat
+    {
+        get
+        {
+            return _maxAngle
+        }
+        set
+        {
+            _maxAngle = newValue
+            
+            if _maxAngle > 360.0
+            {
+                _maxAngle = 360.0
+            }
+            
+            if _maxAngle < 90.0
+            {
+                _maxAngle = 90.0
+            }
+        }
+    }
 }
    
    /// array that holds the absolute angle in degrees of each slice
    private var _absoluteAngles = [CGFloat]()

    public override init(frame: CGRect)
    {

    /// calculates the needed angle for a given value
    private func calcAngle(value: Double) -> CGFloat
    {
        return CGFloat(value) / CGFloat(_data.yValueSum) * _maxAngle
    }
    
    public override func indexForAngle(angle: CGFloat) -> Int
