Re : histogram ROI

[theodoros]

Dear all,

I am making a DAQ system for an Xray detector and I would like to include the functionality of on the fly calibration.

For that I would like to be able to select a ROI from the histogram, fit it, find the centroid and then appoint it to a known energy.

Is there a way to select a ROI from a histogram from the front pannel?

Thanks,

Theodoros

[garrettmarsh]

What are you using to display the histogram? If it is one of the native graphs, cursors are a great way to do this. You can set it up programmatically on init so that there are exactly two cursors with vertical lines only, plus any other properties you want. You can get their positions at any time with a property node, and you can set up events that will fire when cursor is grabbed, moved, and/or released.

Is this what you're looking for?

[Apprenti_Alexandre]

http://zone.ni.com/devzone/cda/epd/p/id/1497#0requirements

In this link, you can find a exemple VI which one show how to implement a ROI on a waveform graph

[theodoros]

Thank you for the replies.

I wanted to know if there is something to be used as a tool like the one I found for selecting a ROI from an image in the Vision palette.

In fact I implemented the solution with the cursors and it works pretty well.

When I finish it I will post it for future reference and comments.

Thanks again.