Hi!
I am facing some performance issues when using a XamDataChart.
I've an example, taken from another post
https://ko.infragistics.com/community/forums/f/ultimate-ui-for-wpf/70986/how-to-bind-multiple-collections-to-single-xamdatachart
I modified this example a little bit so that multiple signals are bound to one common x-axis and one common y-xaxis. There are 5 different signals, each consisting of about 10000 points randomly generated. When a signal is selected or deselected in the listbox the update of the XamDataChart is fast.
This is my first example:
Ex1.zip
Then I modified this example further to include an algorithm to compute a specific signal, 5 times the same signal. This signal is a rectangular signal consisting of about 480 points. Here the update of the XamDataChart is pretty slow (compared to example 1 with about 10000 points)
Ex2.zip
Where does this performance degradation come from?!
How can I increase the performance?!
Best regards,
Christoph
Hello Christoph,
I have been investigating into this behavior that you are referring to, and unfortunately, this is a known limitation of the XamDataChart of the control imposed by the WPF rendering methods used for the chart, and there isn't really too much we can do about it without introducing our own rendering methods.
Essentially, WPF does not play well with a highly fluctuating, seemingly random set of XamDataChart points here because of the Path that is generated as a result of these points. If you were to profile your application using a sort of diagnostic tool, I would imagine that you would see that most of the performance time spent here is in WPF's hardware rasterizer. WPF uses hardware acceleration as its default rendering mechanism, which means it uses Direct2D for rendering via the GPU. This normally makes performance faster, but there is an issue with Direct2D with this type of highly fluctuating shape, in which the rendering algorithm does not work well. This leads to Direct2D needing to do some conversions with the WPF path data, which makes the rendering operations happen primarily on the CPU rather than the GPU, and so there is a performance issue in WPF with this type of fluctuating path geometry.
One question I would like to know in this case is if your real-world data will look like this, or if it will be more linear with less fluctuation? For example, if you take a look at the following forum thread where a similar issue was discussed, I have attached a more-linear sample project with a series that has 1 million data points and the performance is very responsive: https://ko.infragistics.com/community/forums/p/108504/511375.aspx.
If your real-world data will look like this, it is worth re-noting that this issue has come up in the past, and one of our developers has designed a custom-series workaround that uses a custom rendering method to get around this issue. Personally, I don't completely understand a good part of it, but from what I do understand is that it uses a class called WriteableBitmapEx to render the complex geometry of the series' path figure into a bitmap image, which it can then render to the screen. Essentially, it is a custom series with a custom renderer that bypasses the WPF bottleneck that you currently see with the existing series implementations in the XamDataChart, although this series is much less feature-rich than the ones that currently exist in the chart as it is not an "official" series. It is also not maintained, as it is not part of the Infragistics WPF product. You can find more information about the WriteableBitmapEx class here: https://writeablebitmapex.codeplex.com/.
I have also attached the sample project that was created some time ago that uses the custom "ImmediateLineSeries" that works around this issue. Simply check any number of checkboxes at the top of the application and then click one of the radio buttons to specify the number of points that you wish to show in a highly fluctuating, but still very responsive plot.
If you would like to see the ImmediateLineSeries solution more fleshed out into a fully supported series, or perhaps added as a separate rendering method for the chart, I would recommend suggesting a new product idea for this at our WPF Ideas Site, here. This will place you in direct communication with our product management teams who plan and prioritize upcoming features and development based on community and user feedback.
Please let me know if you have any other questions or concerns on this matter.
XamDataChartNoiseDataDemo.zip
Hi Andrew!
Thanks for your investigations.
It is not exactly 100% real world, but it is used to model the signal of a crankshaft position sensor
Information about crankshaft position sensor signals can be found i.e. on
https://gearsmagazine.com/magazine/crank-and-cam-part-ii-howsyour-relationship/
and
http://www.bosch-motorsport.de/content/downloads/Raceparts/Resources/pdf/HIL_Crankshaft_Camshaft_Simulation_75959563__LC_Test_System.pdf
where you will notice this "rectangular" shape.
I've another question in the forum, which deals with representing this signal. Although I've a "rectangular" shape defined by my data points I can only see some kind of "sawtooth" signal due to the rendering and also depending on the chart size.
Maybe it is worth to take a look at that also:
https://ko.infragistics.com/community/forums/f/ultimate-ui-for-wpf/120513/winforms-chart-vs-xamdatachart-visual-representation-of-a-signal-facing-issue/533670
I did not notice the thread you mentioned
https://ko.infragistics.com/community/forums/f/ultimate-ui-for-wpf/108504/datachart-scroll-zoom-performance/511375#511375
because it was related to scroll and zoom performance.
I tried the demo example attached to your reply, but was not able to run it. I currently have version 18.1.20181.324 installed and when compiling I get following error:
'Flattener' does not contain a definition for 'FastFlatten'
Not part of 18.1.20181.324 any more?!
BR, Christoph
I apologize, it does appear that the FastFlatten method was actually split off to another class. If you change the class from Flattener to FastFlattener in the sample project, you should be able to run the sample project I attached. That is:
Flattener.FastFlatten(…); => FastFlattener.FastFlatten(…);
Regarding the other forum thread about the visual representation of the signal in WPF and Windows Forms, this seems to be a rather similar plot shape, but a different issue entirely. It appears you are currently working with another Infragistics support agent on this, and as such, they will continue to look into it and assist you.
I was able to run the demo examply successfully.
I will give it a try because it seems to be a good solution for my problem so far.
Nevertheless, a professional solution available within your products will be a good idea, because it will be maintained and supported officially.
Thank you very much for your support.
I modified the example project XamDataChartNoiseDataDemo a little bit and included my signal-
Modifications include
ChartTestData: added two methods to compute my specific signal shape, one with steps (3,-1) -> (3, 1), and one with steep gradients (3,-1) -> (3.0011, 1).
ChartTestModel:
changed CategoryDataPoint (instead of properties Index and Value I now use X and Y, and both are double).
changed PidDataSet to support changed CategoryDataPoint class
DataChartPage:
added OverviewPlusDetailPane and zoom settings
MainWindow:
two new checkboxes to load my data into the chart
The chart now displays this shape:
instead of something similar to
The modified demo project:
XamDataChartNoiseDataDemo_Modified.zip
I appreciate your hel, because I've no experience with this ImmediateLineSeries.
BR Christoph
Thank you very much.
From my point of view I am ´happy.
Thank you for your update on this matter.
I have been investigating into the reason that the legend badge is not showing up correctly, and this is due to a problem with the Generic.xaml file, in that there does not exist an implicit legend badge for the ImmediateLineSeries, and so the binding that is in place in the LegendItemPointBadgeTemplate does not work.
In the attached modified sample, I replaced it with a Rectangle with its Fill bound to the ActualBrush of the series, and it is now showing up normally. I hope this helps you.
2604.XamDataChartNoiseDataDemo_LegendIssue.zip
Hello Andrew!
Almost satisfied, but .... I've an issue with the legend.
When I use ScatterLineSeries, the legend looks similar to
but when I use ImmediateLineSeriesit looks like
it is not able to show the color of the series properly, instead it shows a undefined image/text, don't know.
I've modified your last example to include a legend:
XamDataChartNoiseDataDemo_LegendIssue.zip
If this can be solved, I have everything I need for the moment.
I would be also glad if it could become an "official" product, because I think that it is a good solution.
I have been investigating into the behavior you are seeing, and I am able to reproduce it, although I’m not sure why this happens in your sample but not in the one that I sent you.
It seems to me that there is something specifically about your dataset that is causing the Viewport of the thumbnail to return an {Empty} Rect with a height and width of different Infinite values, and this is where the issue lies. As such, I have implemented a workaround to check the Viewport for an Empty Rect in the ImmediateLineSeriesWBXView.PrepSurface method prior to calling OnResize as well as surrounding the RenderFrame call in the RenderThumbnail method in ImmediateLineSeries in a try-catch statement. This appears to fix the issue you are seeing and allow the overview plus detail pane to render correctly.
I am attaching a modified version of the sample project you sent to demonstrate. I hope this helps you.
XamDataChartNoiseDataDemo - Kopie (2).zip
I was able to reduce my project to a minimum solution to see the problem. I've attached it:
XamDataChartNoiseDataDemo_MyView.zip
I appreciate your help.