Intensity Graph Cursor Legend Update

[aejulian]

Hello all,

I am currently using an intensity graph to view 2d arrays of data. The graph is setup with two cursors and the cursor legend is visible. I have a scrollbar in the VI so that I can select which dataset to plot (I'm indexing a 3D array to grab a new 2D page).

The issue I'm running into is that after I update the value property of the intensity graph during the scrollbar value change event handler, the cursor legend doesn't update to display the new data that was entered. I am able to get the values to update by incrementing and then decrementing the cursor position, but this adds more latency to the event handler and I would like to try and avoid that if possible (the graph update is not as smooth). Is there a way to force the legend to update without having to do this?

I am running LabVIEW version 16.0.

Thanks,

-Alex

[altenbach]

We need to see some code. 

[aejulian]

See attached for stripped down example code.

[Dafrizzy]

It seems like the legend will only update when the cursor is dragged/moved, regardless of if the VI is running or not. I can't find an obvious property or invoke node that would allow you to manually refresh that update so the best option may be your workaround of programmatically moving the cursor back and forth.

[altenbach]

Yes, it seems you need to "wiggle" the cursors as you do, but all this could be greatly simplified to remove a lot of duplicate code and unnecessary operations. Attached is a very quick draft that possibly could give you some ideas.

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@aejulian wrote:

but this adds more latency to the event handler and I would like to try and avoid that if possible (the graph update is not as smooth).

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The latency is mostly due to your event configuration for the scrollbar: firstly, disable "lock FP until event completes". Also, the "rapidfire" nature at which slides trigger events is a problem, so limit the event queue to 1 for the  scrollbar change.

Also feel free to vote for my old idea here. With it implemented, you could lock the cursor to the plot and none of your rounding would be needed. Even better, also vote for this related idea. 😄

[aejulian]

Thanks for the input and the quick code draft, it gave me some good ideas to use moving forward. I forgot about those options with the events as well, thanks!

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@altenbach wrote:

Also free free to vote for my old idea here. With it implemented, you could lock the cursor to the plot and none of your rounding would be needed.

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As it turns out, I ran into that idea exchange post while I was still figuring out how to get the intensity graph setup correctly  

[aejulian]

So if it is settled that the behavior of the graph isn't correct in the current implementation, what is the best path forward with this? Migrate this to the idea exchange, submit it as a bug, or something else?

-Alex

[Dafrizzy]

Alex,

Feel free to submit it as a bug if you feel the workaround is not acceptable so that we can get R&D to review it more in-depth. My guess is that it would be classified as a feature request instead of unexpected behavior. Feel free to post it on the idea exchange as well! R&D does look through there regularly to see what features users are looking for. However, I couldn't find much past information on other users who ran into this issue so it may get more traction/visibility if it is filed as a service request.