Recommended plot type with fixed max size - DateTime/double

[bukkideme]

ScottPlot Version: 4.1.57

Operating System: win10 x64

Application Type: Winforms, .NET Framework 4.8

Question:
Hi! I am looking for best practice. I need to plot maximum 24 hours * 60 min * 60 sec data, two data channels. X axis should show DateTime, Y and Y2 axes should show the double values of the two channels, as two curves. The two channel data points have the same common DateTime X value.
The data is collected incrementally, and old data is not changing, but after the specified size, I need to throw away older points as new ones coming in.
What plot type should I use? What would you recommend?
Thanks very much!

[Xerxes004]

What have you tried so far? Is two ScatterPlot not cutting it?

You might also be able to accomplish this with the FunctionPlot as well if you're running into speed issues. But my guess is ScatterPlot is plenty fast.

A couple things that come to mind:

• You should be able to save some wall-clock time by updating the underlying arrays in parallel
• Both plots can share the same X array, so you only need 3 arrays total
• 1 second should be plenty of time to update the underlying data, even without parallelization

[bukkideme]

Thanks, ok, so 86400 * 3 data values should not be an issue even for a ScatterPlot. When I want the user play with the data, it will have a "pause" option so it is not updating it with the 1 Hz speed, so no issue when the user wants to zoom in, etc.
So I could go with 2 ScatterPlots then...

Actually I also came across the so called "ScatterList" type, what about using it in this case? So I do not need to program my own buffer for the data, I just add points to the Lists, and remove older ones as they reach the 24h limit...?
https://scottplot.net/cookbook/4.1/category/plottable-scatter-plot-list/

Thanks for any suggestions! :)

[Xerxes004]

I don't have any experience with the ScatterList, but you can accomplish this pretty easily on your own with .ToArray() and regular scatter plots.

Are you concerned about speed or size or what?

[bukkideme]

Well, i guess this size of data should not be an issue whatever i use. I just wanted to ask other people what they would use. Thanks for the suggestions! :)

[Xerxes004]

No worries! Good luck

[swharden]

https://scottplot.net/faq/live-data/ may have some strategies you'll find useful! I suspect the partial array rendering will be useful: You can create a scatter plot from a fixed-length array with 1 day of space for data, set MinRenderIndex and MaxRenderIndex to indicate the "valid" data to display, and move MaxRenderIndex as you fill new data values into the existing array

If you are displaying data sampled at a fixed interval, definitely use the signal plot instead of the scatter plot! It will be MUCH faster.

You probably already know this, but just in case keep in mind that a DateTime axis can be achieved using ToOADate() to convert DateTime to double, as demonstrated in https://scottplot.net/cookbook/4.1/category/axis-and-ticks/#plotting-datetime-data