Hi!
In a series of data I would like to identify some specific points. I just made up a real simple table which is supposed to illustrate a jump cycle to try the math. I need to be able to identify three specific points
-the start of the eccentric phase (which is when velocity becomes negative, IE the force drops from the original value)
-start of flight time (which is when force is zero)
-the end of flight time (which is on landing when force rises)
So because the real data series in a jump like this includes well over 1000 values I simplified a series just to figure out the math so I would be able to check that I've done it right.
I started out with trying to find the start of the eccentric phase. Because the force will vary a little bit before the jump is executed I figured that the point I should identify as the start of the eccentric phase is when "the force drops equal to or less than 90% of the original_value". Then I would be sure that the data I get is the start of this phase and not only small changes in the "weight".
I would like excel to display the time point at which the above statement is true.
I tried using a IF(OR.. formula to do the logical test for finding the value, but what I haven't been able to do is having excel display the time point. I can only get excel to display a text which tells me if this is true or not.
My example table looks like this:
Force (N) Time (ms)
834 (original_v) 100
700 234
550 310
0 395
0 475
0 585
510 690
2545 780
7400 860
So obviously the first value in this series which is equal to or less than original_value (834 N) - 10% is 700 N and the time point I would like Excel to display for me is at which time this is true, 234 ms.
Anyone who could help me out here? I need to identify all the three points so if someone can help me out with this it would be great!!
NB! If the table in the text doesn't work out, just download the attachment, it shows the table and data
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