The trackball visuals are the ellipses that snap to the data points when you enable the trackball behavior and hover the plot area. If a trackball is displayed and you zoom-in (via mouse wheel) or pan (via drag), the trackball visuals stay on the proper data point as expected. However, if the zoom-in forces the corresponding data point to go outside the viewport, the trackball follows it and it doesn't get hidden (because it is outside the viewport/plot area).

To work this around, you can manually hide the Ellipse visuals.

private void RadChart_PanOffsetChanged(object sender, Telerik.Windows.Controls.ChartView.ChartPanOffsetChangedEventArgs e)
{
	Dispatcher.BeginInvoke(new Action(() =>
	{
		var chart = (RadCartesianChart)sender;
		var trackballs = chart.ChildrenOfType<Ellipse>().Where(x => x.DataContext is DataPointInfo);
		foreach (Ellipse visual in trackballs)
		{
			var dpInfo = (DataPointInfo)visual.DataContext;
			RadRect dpSlot = dpInfo.DataPoint.LayoutSlot;
			if (!chart.PlotAreaClip.Contains(dpSlot.X, dpSlot.Y))
			{
				visual.Opacity = 0;
			}
			else
			{
				if (visual.Opacity == 0)
				{
					visual.Opacity = 1;
				}
			}
		}
	}));
}

NullReferenceException when MinorTicksPerMajor of the axis is set and the chart gets unloaded.

To work this around, avoid setting the MinorTIcksPerMajor property in this scenario.

The exception can be observed when you a plot data point with value that falls outside of the range of the Decimal type.

As a workaround you can coerce the data before give it to the chart.

Implement a new LabelFitMode that prevents the axes labels from overlapping by increasing the LabelInteval.
Declined: This is no longer necessary after introducing the SmartLabelsMode.

I would like to be able to create a histogram where both the x and y axis are linear series and where I can specify the start and end position of each bin (not just one). Previously described workarounds include using StepLineSeries and bar series which cannot have two linear series. I cannot use a scatter plot series as they do not provide the step-wise look of the histogram.  Please add this support! 

The FadeOtherSeries hover mode doesn't work when the lightweight render options (Direct2D and Bitmap) are used.

You can find one way to work this around in the attached project.

ArgumentException occurs when the ItemsSource of the chart series is populated with items that implement the ICustomTypeProvider interface and the value binding properties of the series  (ValueBinding, CategoryBinding, YValueBinding, XValueBinding, etc.) are assigned to dynamic properties. This happens when the value binding properties are assigned to PropertyNameDataPointBinding object pointing to a property name. This is also what happens if you set the properties in XAML using string values.

To work this around, you can use the GenericDataPointBinding<T> class defined in code-behind in order to assign the value binding properties. 

Or alternatively, you can implement custom PropertyNameDataPointBinding class and override its GetValue() method. In the method, you can check the item type and if it is ICustomTypeProvider, and then execute custom code that gets the value. The custom PropertyNameDataPointBinding implementation is shown in the attached CustomPropertyNameDataPointBinding.zip file. To use the custom binding class in XAML, you can use the following syntax:

<telerik:ScatterPointSeries.YValueBinding>
	<local:CustomPropertyNameDataPointBinding PropertyName="Y" />
</telerik:ScatterPointSeries.YValueBinding>

The SeriesCreated event of the RadChartView's SeriesProvicer is never called when the SeriesDescriptorSelector property is used.

To work this around, you can create a custom chart series descriptor and override its CreateInstanceCore method.

public class CustomScatterSeriesDescriptor : ScatterSeriesDescriptor
{
	protected override ChartSeries CreateInstanceCore(object context)
	{
		var series = (ScatterSeries)base.CreateInstanceCore(context);
		// assign whatever settings you need here
		return series;
	}
}

ChartView: Add support for axes rendering, when no data is available

As a workaround add a series with one point and set its color to transparent.

<telerik:ScatterLineSeries XValueBinding="."
                  YValueBinding="."
                  Stroke="Transparent">
    <telerik:ScatterLineSeries.ItemsSource>
        <x:Array Type="system:Int32">
            <system:Int32>0</system:Int32>
        </x:Array>
    </telerik:ScatterLineSeries.ItemsSource>
</telerik:ScatterLineSeries>

Create 2-dimensional contour plot from unstructured 3-dimensional data.  Means the points are randomly arranged in the XY plane.

Attached file shows an example of what I would like to achieve.  I think the contour plot Telerik does currently requires a structured grid, i.e. full grid of NxM points.

Please add the Contour series for showing the scatter (X,Y) lines which are connecting the points with the equial Z- coordinate. Currently a scatter 3D surface (X,Y,Z)  can now be shown only as 3D chart.

Often it is necessary to show 3D surface as 2D chart with lines connecting (X,Y) points with "same Z-level" .

Samples:

• Geographic map showing the contour lines of the same height: https://en.wikipedia.org/wiki/Contour_line ,
• Map of the points with the same temperature inside the 3D container,
• ...

References:

• https://www.infragistics.com/help/winforms/datachart-scatter-contour-series 
• https://www.infragistics.com/help/winforms/geographicmap-using-geographic-contour-line-series 
• https://mathworld.wolfram.com/ContourPlot.html 

Support for displaying error bars

The problem arises when we have many graphs on one window and when we scroll to the bottom then to the middle of the window and then resize the width of the window, not all graphics dynamically resize, some harden to the previous size.

I am attaching a project in which you can reproduce the problem.

And I am attaching a video where the problem is clearly demonstrated.

Please solve the problem as soon as possible for our product it is critical!

LabelRotationAngle applies to labels only in horizontal axis.

It is mainly needed in Vertical axis, when the chart is rotated externally, when placed in rotated panel or control. In this case the vertical axis take the role of a horizontal axis visually and easy way to rotate all labels is needed for readability.

Add the option for having separate PanZoomBars for each axis, so the user can scroll/zoom each axis independently from the other axes.