Counting peaks/ Cycles

[Kemi]

Is there a way to count each time this peak in a day? I'm having trouble because it doesn't peak or fall at the exact same number every time. I could do it within a range and that might work. Any suggestions are welcome.

[Joe Reckamp]

Hi Kemi,

Using the derivative can be very helpful to find peaks in your data. It appears your data seems to increase without too much noise (in terms of small peaks on the way towards the main peak) so I doubt you would need too much data cleansing first. So you may be able to simply do a derivative by using the Formula tool:

$signal.derivative()

That will then show a positive value when you are increasing, a negative value when you are decreasing, which means that the point at which it goes from positive through zero to negative would be the high point of your peak. Therefore, I would then find when the derivative is positive (> 0) using a Value Search. You'll also want to make a Periodic Condition for "Daily" that represents when you want your days to start and end. From there, you should be able to use Signal from Condition to count the ends (remembering that the end of the positive section is when the peak occurs) each day.