Determine maximums and minimums of empirical data

Hi

I need to determine values of the tops and bottoms of a curve in a graph. In the attachment it can be seen that the data generated produce a hill/valley like pattern. Does anyone know of a good way to find the top/bottom difference (on the y-axis) between each of the changes. I guess you could say I am looking for the amplitude changes. The actual curve is muuuch longer, hence automation is a good thing.


Regards

StefanBG

I'm not sure is this it.. but look and say your opinion:

Top_bottom_determination(1).xls

As you can visually see on graph... the greater is difference between max and min, the greater is peak on second graph.

You can filter them out by custom filter greater than 0,01 OR less than -0,01

(choose custom numbers depending do you like those double peaks or not to be included).

If you want both of them in same direction just add ABS function:

=ABS(ATAN((A3-A2)/A2))

Thank you Zbor.

I think it may be on the right track. I hadnt considered this option.
Do you have an idea how get from your suggestion to one where I am able to get the actual values of the minimums and maximums? So that it tells me the level of the peaks (150,142, 148, 154, 147 etc.)

Regards

StefanBG

I hope someone better wil help you. I just don't have idea

No worries. Now I have something to work from. Thanx again for your effort.

Since noone else didn't reply, here are some thoughts (I say thoughts not soultion becaus ethere is bunch of helping columns...

Top_bottom_determination(1)(1).xlsx

L1 is place where is biggest difference (biggest peak on graph)

And below all peaks listed

Zbor - you are a genius. This takes care of what I want to do. What I am going to do now is just modify it a little so that it will take the average of some of the values in the identified peak tops and bottoms (to avoid too gross outliers).
Thank you for your help and time.

Originally Posted by zbor

Since noone else didn't reply, here are some thoughts (I say thoughts not soultion becaus ethere is bunch of helping columns...

Attachment 56464

L1 is place where is biggest difference (biggest peak on graph)

And below all peaks listed