Scrollable line chart

[Ben Tanner]

I am using a line chart to plot a real-time graph. I am trying to find a way to set the chart to scroll and keep the most recently added point on screen. The samples I have found so far show have scrolling when the user zooms in on a portion but that is not what I need. Different combinations of the ScrollViewer properties have had no impact but maybe I am not using those correctly either. Is there a way to set up a sliding window type view?

[Pavithra J]

Hi Ben,

Thanks for your interest in Syncfusion products.

We are having a sample illustrating this feature in our installation.

If you have our products(v7.2.0.20) installed in your system, you can get the sample (Range Scrolling Demo) under the Category "Chart Performance".

Local Link: \\... \Syncfusion\EssentialStudio\7.2.0.30\WPF\Chart.WPF\Samples\3.5\WindowsSamples\Chart Performance\Range Scrolling Demo

If not, make use of the below given link to download the sample. Could you please check the sample and let us know if it helps.

Download Link:

RangeScrolling Sample

Please let us know if you have further queries.

Regards,
Pavithra.J

[Ben Tanner]

I did see the Range Scrolling example though this is not what I am after. The demo you refer to allows you to scroll through ranges of static data. My application adds data dynamically. Currently the x-axis adjusts the maximum in order to add the new point. The minimum value stays the same so the graph starts to get squished after a number of points have been added.

While the slider bar is nice for going back to view past data what I need is a way to have the graph itself adjust the x-axis range values to maintain a consistent number of points in the view. As a new point is added the graph should adjust to include the new point and the oldest point would no longer be visible.

[Pavithra J]

Hi Ben,

Thanks for your interest in Syncfusion products.

As far as your requirement is to scrollback to the old points, we have created a sample in which scrolling can be done by panning the chart area.

You can download the sample from the below given location.

Sample-Sliding ChartArea

Here, Click on the chart area and drag towards left for scrolling back. This sample allows both left and right panning.

Please let us know if you have further queries.

Regards,
Pavithra.J

[Ben Tanner]

The example helped me figure out how to adjust the display range based on a number of readings. I will keep playing around with it to see if I can get exactly what I need. This did point me in the right direction. Thanks.

[Pavithra J]

Hi Ben,

Thanks for your update.

Please let us know if you have further queries.

Thank you for choosing Syncfusion products.

Regards,
Pavithra.J

[Administrator]

Ben,

Following up on our conversation over the phone, you can make the first point flush with the Y axis by setting RangePadding = None on the PrimaryAxis.

Take a look some documentation here:
http://help.syncfusion.com/User%20Interface/WPF/Chart

Some sample source:












This is also illustrated in the sample attached in the previous update.

Regards,
Praveen

[Ben Tanner]

The samples have helped me see the properties you were referring to. Unfortunately setting the RangePadding="None" has not made the anticipated adjustment. I am attaching a screenshot of my test application to illustrate what I am seeing.

The initial point is not lined up with the Y-axis. In fact the labels do not line up as I expect either. The first label is not on the axis and the last label is beyond the end of the graph. It is almost as if the first point is placed in index 1 instead of index 0. One difference I can see is that I am using DateTime values for the X-axis. All of the samples provided have used a numeric value. Is there a problem when using DateTime values maybe?



Xaxis offset_c3188be3.jpg

[Pavithra J]

Hi Ben,

Thanks for your interest in Syncfusion products.

Could you please check with the sample , whether RangePadding for both the axes is set as None. If not kindly do it. Also check by setting IsIndexed property of ChartSeries as False.

If you could still reproduce the issue , kindly update us with a simple sample illustrating the issue as we didn't come across such issues already.

Please let us know if you have further queries.

Regards,
Pavithra.J