RadChartingKit and Large Data Samples

[Terry]

The RadChart has the Sampling feature for dealing with the situation where there are thousands of data points to display. I don't see a similar type of feature for the RadChartingKit.

Have I missed something or is this something that will be added before release?

[Vladimir Milev]

Hi Terry,

We will be shipping this functionality with the next beta scheduled to go with Q3 release. This functionality will be part of a new ChartDataSource control, and will feature a brand new type of sampling - datetime sampling.

Stay tuned for the release!

Best wishes,
Vladimir Milev
the Telerik team

[Terry]

Hi Vladimir,

Thanks for your response. Could you please clarify for me what will be beta and what will be released in the Q3 release.

Terry

[Giuseppe]

Hello Terry,

The new chart control will keep the BETA tag throughout the coming Q3 2011 release and will be officially announced  as v1.0 in Q1 2012.

Here are some of the most important highlights:

• Performance: exceptional performance, intuitive and easy-to-use model and pixel-perfectness were some of the major tasks we have set for this new control.
  • We have separated the chart into several layers, where the core one is totally platform agnostic and is built on top of our custom logical tree. We call this layer the “View Model” of the chart.
  • We have a custom property store used within the charting logical tree. It is about 5 times faster than DependencyObject in look-up time and consumes about 3 times less memory.
  • We have an entirely custom layout and do not rely on the SL layout system to arrange our charting view models.
  • We have a stand-alone visualization layer that presents the chart view model. Every view model is presented by the simplest possible SL visual – e.g. Rectangle, Line, Polyline, etc. Still, every single aspect is fully customizable by specifying Data Templates or Styles.
  • We use Canvas – the only SL panel that does not invalidate measure automatically. When a redraw of some charting part is required, we simply update the Width, Height and Canvas.Left, Canvas.Top properties of the corresponding visual. A simple test proved that calling InvalidateMeasure of the canvas upon a change the in view model degrades performance about 10 times.

• Architecture: a number of chart controls built for a specific purpose vs one monolith control (provides cleaner, simpler, and relevant API)

• RadCartesianChart -- hosts Bar, Area, Line, Spline, SplineArea, ScatterPoint, Candlestick, and OHLC series types (and their horizontal & stacked / stacked100 equivalents where applicable).
• RadPieChart -- hosts Pie series type.
• RadPolarChart -- hosts PolarLine, PolarArea, PolarPoint, RadarLine, RadarArea, RadarPoint series types (Radar series types will be added for Q3 release).
• Notable features
  • Financial indicators (will be added for Q3 release) -- support for about 20 most common financial indicators to complement the data visualization for all cartesian series types.
  • Extended DateTime support built-in in the axes' logic
    • DateTimeCategoricalAxis -- Specialized categorical axis that expects each data point to provide a System.DateTime structure as its value for this axis. The points are grouped by a user-defined date-time component (Year, Month, Day, etc.) and then the groups are sorted chronologically.
    • DateTimeContinuousAxis -- Specialized axis that expects each data point to provide a System.DateTime structure as its value for this axis. May be thought of as a timeline where the coordinate of each data point is calculated depending on the position of its associated DateTime on the timeline. The base unit (or the timeline step) of the axis is calculated depending on the smallest difference between any two dates.
  • Support for linear and logarithmic axes.
  • Built-in data sampling (with extended DateTime awareness, will be added for Q3 release)
  • Behaviors:
    • PanAndZoom Behavior (will be added for Q3 release) -- with smooth scrolling support.
    • TrackBall Behavior (also known as current value indicator, will be added for Q3 release) 
    • ToolTip Behavior (will be added for Q3 release)

Hope this helps.


Regards,
Giuseppe
the Telerik team

[Terry]

So we wouldn't be able to use the new chart control in production software until it is released in Q1 2012?

Terry

[Giuseppe]

Hello Terry,

Generally we are happy with the stability of the forthcoming release but we decided to keep the BETA tag for the Q3 release based on several factors:

• Series item labels support could introduce some breaking changes for the Q1 release as we are not completely satisfied with the implementation at the moment.
• Behavior support -- we have partial support for selection / tooltips (only for item-drawn series) and it is possible that some breaking changes will be necessary when implementing the same features for continuous series (line, spline, etc).
• MVVM support -- to optimize the performance of the control not all of the available control properties are exposed as dependency properties and this obviously will not work perfectly with all MVVM scenarios. We are still evaluating what the balance should be (should there be any) and we will take the final decision based on customer feedback as well.

So generally you can consider the Q3 2011 release as having "Go Live" license, although we recommend you to evaluate the control suitability on project by project basis (e.g. if you need top-notch performance, polar / radar series, support for financial indicators, or current value indicator you will probably pick new control as the current RadChart does not support any of these features).


Regards,
Giuseppe
the Telerik team