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Identifying Peaks and their Rate of Change


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Hello everybody,

I am very new to SEEQ and have the following problem/question:

I would like to identify each maximum peak of the blue curve (shown below in the figure). Then I would like to compare each maximum peak's value - meaning something like the rate of change of lets say one peak and the upcoming peak. In the end I want to detect a significant change of the signal (marked by red X's) and would like to know its duration (marked by the red arrows).
 

Thank you.

Regards Matthias395914719_SeeqQuestion.thumb.jpg.6f7672f89cb2bfe27526e0460c22d295.jpg

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Hi Matthias, 

The first question is to identify each maximum peak of the blue trend 

1. First apply an agileFilter to remove noisy signal and calculate the derivative of the signal. Please refer to formula documentation for derivative. Example: 

$signal.agileFilter(15min).derivative('min')

2. Then use value search to identify increasing trend, example as below and you can optimize accordingly. 

image.thumb.png.e731c0bafabf527a126e226bd8a677bb.png

or you can refer to step 4 and 5 from this post : 

3. Use Signal from condition to find the maximum value bounded to the condition created in step 2 and place the timestamp at point of max value: 

image.thumb.png.83a6b85537f40c7883f4fa0d946e6997.png

 

Second Question : Rate of change of one peak and the upcoming peak

4.  We can apply the same derivative function. Example: 

$max.derivative('min')

 

Third Question to detect a significant change of the signal (marked by red X's)

5. The max derivative will increase or decrease significantly when there's a sudden change. Example here, we're using the threshold of +-0.005 to detect the changes for max rate decrease and increase respectively. 

image.thumb.png.e2bd7e0d49c376b3ff66db85684c4756.png

 

Forth Question to know its Duration (marked by the red arrows) : 

6. Use Composite condition to join ''Rate Decreased'' and ''Rate Increased"

image.thumb.png.797a68279938572be21638abbf9f9c85.png

8. Calculate Total Duration of ''Join Decreased to Increased'' condition using signal from condition tool. 

image.thumb.png.0e8fcb9c1c81c9ea2af42217cd67edb5.png

Please give this a try to your signal and let us know if you have further question. 

 

 

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