Clear Chart and set XAxis range

[thade.oconnor]

Hi,

I have a WPF data series chart which I need to clear based on a user request. The plot has time on the X axis, in the format MM:SS. The only problem is that when I set the XAxes range to SetRange(0, plotXrange) - to reset the axis lables (to start at 0:00), that if the plot has been running for more than a (approx) minute it will reset to 1:00 (or 2:00 if longer than two minutes of run time).

Is there a different function call required? I've checked through your PDF, however couldn't find anything that was more appropriate.

Reset code included below:

//This is only called on reset event.

Code: Select all

m_chart.BeginUpdate();
{
                foreach (SampleDataSeries sds in m_chart.ViewXY.SampleDataSeries)
                {
                    sds.Clear();
                }
                m_chart.ViewXY.XAxes[0].SetRange(0, plotXrange);
}
m_chart.EndUpdate();

[ArctionPasi]

Hi Thade,

I believe the correct LabelsTimeFormat is "mm:ss". MM is for months.

To check I've understood your goal correctly... in the reset command, you want the labels start at 0:00. Your SetRange makes that correctly. Probably the problem is in sds.FirstSampleTimeStamp, which you should set to 0 too.

I hope it helps...

[ArctionPasi]

...and set xAxis.ScrollPosition = 0, that is the real-time scroll position property which makes the chart scroll, sweep or step with optimal efficiency. xAxis.SetRange is not needed.

[thade.oconnor]

Hi,

I've added xAxis.ScrollPosition = 0. This has generally worked however I have noticed sometimes that the chart will restart in the center of the graph.

Note: that my chart is reversed (which may be a factor).

Have you got any idea that might be happening with my plot.

Regards,
Thade

[ArctionPasi]

Are you sure you have set FirstSampleTimeStamp to 0? And if you are keeping the latest X value in a member variable, remember to reset it too. m_dCurrentX = 0.

I tested with Thread-fed multi-channel data example. I just set xAxis.Reversed = True. Other code changes I didn't make. By setting Scroll mode to Scrolling, and using Starting, Stopping and Starting again worked correctly. Your Reset operation should be pretty much Like Stop and Start, right?