How to plot a filled box under a waveform plot?

[RipRock99]

Hello all,

I have a 3000 point waveform graph showing a series of peaks.  For one of these peaks, for which I know the starting and ending indices, I would like to programmatically draw a filled box under the waveform on the graph, to highlight it's position.  I can't figure out if there is a way to do this.

I have figured out how to draw cursors at the begin and end, but ultimately I do this for multiple peaks, and the forest of cursors rapidly becomes confusing.  A simple shaded box would work far better.

Any ideas?

Many thanks in advance,

RipRock99 

[GerdW]

Hi RipRock,

which LV version do you use?

2 options come to my mind:

- make the background of thegraph transparent, puta picture indicator behind it and draw rectangle here (suitable for older LV versions)

- use the possibility to put pictures "into" the graph and draw rectangles here (for LV8+ AFAIK, property PlotImages [Front, Middle, Back])

[Coq_Rouge]

is it something like this

[RipRock99]

Thanks for the idea - will check it out shortly.  I am using LV 8.5.1 (soon to be replaced on my system with LV 2009).

[RipRock99]

Whoops - OK - I can't see the 8.6 vi.  Can you downgrade it to 8.5.1 or take a picture of it?

Thanks!

[GerdW]

Hi RipRock,

now you know why I asked for the LV version in the first place

Attached is the VI in LV8.5. It uses the plot fill option to fill to -Inf, an easy option to check for you!

[RipRock99 · Accepted solution]

Big Thanks GerdW!

The LV code was very close to what I wanted to do, and was easy to use to determine how to make my code produce the result I sought.  Basically, I added another waveform to my graph, using my known x-indices to set the Y values for the areas I wanted to be gray as +infinity, and the leaving the remainder at = -infinity.  I then plotted this second graph on top of the original waveform, and used the property node to set the fill flag to -infinity.

This doesn't answer the general question of how to draw a filled box with known coordinates on a graph, but this does solve what I wanted to achieve!

Well done, and thanks,

RipRock99

PS:  I include a snapshot of the result, and a snapshot of the code used to set the property node programmatically.  I don't include my whole code as it is way complicated, and I would also need to add a big dataset.  Hope the pictures are enough to help anyone else referencing this board!

[RipRock99]

Here are those links as inline images.  Apologies - I didn't quite see how to do this in the previous post.

Here is the property node code:

And here is the result: