Until the feature gets implemented please use the suggested solution here: http://www.telerik.com/support/kb/winforms/details/integrating-panzoom-trackball-and-lassozoom-controllers-in-radchartview

There are three ways in which null values can be handled:

1 . Zero. When this option is used, each null value is replaced with a zero. The data entry is not removed from the data collection. Only its original null/empty value is replaced with zero. 
2 . Gap. This option visually removes the regions for each set of empty(null) points. The data entry is not removed from the data collection. Essentially, it connects the points neighboring the null point (or the collection of empty values).
3 . Drop - this option clips, or visually removes each section/segment, corresponding to a set of empty points/values. 

The trackball does not work well when charting the dxf cad drawing of a circle or more complex shape

would be better for it to have cross hair mode,  as single point mode does not work (as it picks up a massive array of x,y points in the tooltip, making it unmanageable)

Showtrackball = true
SelectionMode = SingleDataPoint

Telerik.Charting namespace exist in the WinForms and the WFP assemblies and one cannot reference both in a single project.

Add Three Line Break Series to RadChartView

Add Point and Figure Series to RadChartView

Add Kagi Series to RadChartView

Add Renko Series to RadChartView

RadChartView should visualize the pan and zoom state of a view through a scroll bar

To reproduce:
- Use HTML- like text formatting in the chart title.
- Export the chart to image.
- The tags are shown in the text.

Workaround:
private void radButton1_Click(object sender, EventArgs e)
{
    radChartView1.ShowTitle = false;

    TextPrimitiveHtmlImpl impl = new TextPrimitiveHtmlImpl();
    TextParams textParams = this.radChartView1.ChartElement.TitleElement.TextParams;
    SizeF size = impl.MeasureOverride(new SizeF(500f, 200), textParams);

    using (MemoryStream stream = new MemoryStream())
    {
        radChartView1.ExportToImage(stream, new Size(500, 500 - (int)size.Height));

        Bitmap bmp = new Bitmap(500, 500);

        using (Graphics g = Graphics.FromImage(bmp))
        {
            g.Clear(Color.White);
            textParams.paintingRectangle = new RectangleF(Point.Empty, size);
            impl.PaintPrimitive(new RadGdiGraphics(g), textParams);
            g.DrawImage(Image.FromStream(stream), 0, size.Height, 500, 500 - size.Height);
        }

        bmp.Save(@"D:\xfile.bmp");
    }

    radChartView1.ShowTitle = true;
}

Workaround:

 Sub New()

     InitializeComponent()

     AddHandler Me.RadChartView1.CreateRenderer, AddressOf CreateRenderer
     
     AddHandler Me.RadChartView1.LabelFormatting, AddressOf LabelFormatting 
     Dim barSeries As New Telerik.WinControls.UI.BarSeries("Performance", "RepresentativeName")
     barSeries.ShowLabels = True

     barSeries.DataPoints.Add(New CategoricalDataPoint(177, "Harley"))
     barSeries.DataPoints.Add(New CategoricalDataPoint(128, "White"))
     barSeries.DataPoints.Add(New CategoricalDataPoint(143, "Smith"))
     barSeries.DataPoints.Add(New CategoricalDataPoint(111, "Jones"))
     barSeries.DataPoints.Add(New CategoricalDataPoint(118, "Marshall"))
     Me.RadChartView1.Series.Add(barSeries)
     Dim barSeries2 As New Telerik.WinControls.UI.BarSeries("Performance", "RepresentativeName")
     barSeries2.ShowLabels = True
     barSeries2.DataPoints.Add(New CategoricalDataPoint(153, "Harley"))
     barSeries2.DataPoints.Add(New CategoricalDataPoint(141, "White"))
     barSeries2.DataPoints.Add(New CategoricalDataPoint(130, "Smith"))
     barSeries2.DataPoints.Add(New CategoricalDataPoint(88, "Jones"))
     barSeries2.DataPoints.Add(New CategoricalDataPoint(109, "Marshall"))
     Me.RadChartView1.Series.Add(barSeries2)

 End Sub

 Private Sub LabelFormatting(sender As Object, e As Telerik.WinControls.UI.ChartViewLabelFormattingEventArgs)
     Dim dataPoint As CategoricalDataPoint = TryCast(e.LabelElement.DataPoint, CategoricalDataPoint)
     e.LabelElement.Text = "Value: " & Environment.NewLine & dataPoint.Value
     e.LabelElement.BackColor = Color.Yellow 
 End Sub

 Private Sub CreateRenderer(sender As Object, e As ChartViewCreateRendererEventArgs)
     e.Renderer = New CustomCartesianRenderer(TryCast(e.Area, CartesianArea))
 End Sub

 Public Class CustomCartesianRenderer
 Inherits CartesianRenderer

     Public Sub New(area As CartesianArea)
         MyBase.New(area)

     End Sub

     Protected Overrides Sub Initialize()
         MyBase.Initialize()

         For i As Integer = 0 To Me.DrawParts.Count - 1
             Dim labelPart As BarLabelElementDrawPart = TryCast(Me.DrawParts(i), BarLabelElementDrawPart)
             If labelPart IsNot Nothing Then
                 Me.DrawParts(i) = New CustomLabelElementDrawPart(DirectCast(labelPart.Element, BarSeries), Me)
             End If
         Next
     End Sub
 End Class

 Public Class CustomLabelElementDrawPart
 Inherits BarLabelElementDrawPart
     Public Sub New(owner As ChartSeries, renderer As IChartRenderer)
         MyBase.New(owner, renderer)
     End Sub

     Public Overrides Sub Draw()
         For Each dataPointElement As DataPointElement In Me.Element.Children
             For Each label As LabelElement In dataPointElement.Children
                 label.ForeColor = Color.Transparent
             Next
         Next

         MyBase.Draw()
         Dim graphics As Graphics = TryCast(Me.Renderer.Surface, Graphics)
         Dim radGraphics As New RadGdiGraphics(graphics)
         Dim slot As RadRect
         Dim rect As Rectangle
         Dim stringFormat As New StringFormat()
         stringFormat.Alignment = StringAlignment.Center
         stringFormat.LineAlignment = StringAlignment.Center

         For Each dataPointElement As DataPointElement In Me.Element.Children
             For Each label As LabelElement In dataPointElement.Children
                 label.ForeColor = Color.Transparent
                 slot = label.GetLayoutSlot()
                 slot = AdjustLayoutSlot(slot, label.DataPointElement)
                 rect = ChartRenderer.ToRectangle(slot)
                 Using brush As Brush = New SolidBrush(Color.Red)
                     Dim drawLocation As New PointF()
                     drawLocation.X = rect.X + label.Padding.Left
                     drawLocation.Y = rect.Y + label.Padding.Top

                     graphics.DrawString(label.Text, label.Font, brush, rect, stringFormat)
                 End Using
             Next
         Next
     End Sub
 End Class