How to set different threshold's for each data?

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I am plotting a graph of acceleration(y axis) Vs time(x axis) for 1000 points(secs). I want that particular point at which value is greater than threshold. But if its for single data I can use this code :
firstIndex = find(Acceleration > 43 ,1, 'first');
AccelerationAtThresh = Acceleration(firstIndex);
timeAtThresh = time(firstIndex);
I have many data's and for each data there is different threshold to be set.
Say,for the 1st data (which I have attached) it should show 43
How can I proceed?
Can this be used in real time information gathering as well?
I have attached the flow chart for reference

Answers (1)

Image Analyst
Image Analyst on 13 Sep 2022
First I'd ask why you need a different threshold for each one. Is there drift in your measurement that can possibly be avoided, thus allowing you to use a fixed threshold, which is usually preferable?
Otherwise you'll need an automatic thresholding algorithm. You didn't post the plots (why not?) and I didn't bother to download the spreadsheet and write a MATLAB program to plot all your curves, so I don't know what to suggest (make it easy for us to help you, not hard). Perhaps findchangepts or my attached triangle threshold might work.
  4 Comments
Image Analyst
Image Analyst on 14 Sep 2022
OK, but what is there in that fairly noisy signal that tells you 43 should be the time chosen to be a threshold?
And what do you want to do with that time threshold? Extract data after that? Extract data before that?

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