             var e = _yVals.removeAtIndex(index);
             
             _yValueSum -= e.value;
-            calcMinMax();
+            calcMinMax(start: _lastStart, end: _lastEnd);
             
             return true;
         }

    internal var _yMax = Float(0.0)
    internal var _yMin = Float(0.0)
    internal var _yValueSum = Float(0.0)
    public var label = "DataSet"
    public var visible = true;
    public var drawValuesEnabled = true;

        // default color
        colors.append(UIColor(red: 140.0/255.0, green: 234.0/255.0, blue: 255.0/255.0, alpha: 1.0));
        
        self.calcMinMax(start: _lastStart, end: _lastEnd);
        self.calcYValueSum();
    }
    
