How to detect variations in data?
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I would like to determine the location at which there is data variation (like the highlighted points in the attached image).
Kindly find the attached code + .mat file.
Each sub-plot represents a variable on y-axis and the time on x-axis. Usually, the variation appear in several variables (plots) like this one.
Could you suggest the best method to do so?
and How can I determine the starting and ending points of that variation?
I appreciate your help.
Image Analyst on 24 Dec 2019
You might try movstd() to do a sliding window standard deviation. Then threshold it to find elements where the standard deviation is what you deem "high". See attached code where I did it for your "B" signal. Adapt it to do any other signals you want.
More Answers (1)
Ridwan Alam on 23 Dec 2019
Depends on how complex of a solution you are looking for. There are algorithms for change point detection that you can try.
Or, you can have a sliding window (your defined size) over the signal and look for specific features (e.g mean crossing rate, variance, etc. depending your signal type) to find the windows that contain a "change".
Hope this helps.