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altbeb
08-08-2011, 08:42 PM
Hi:

been knocking around this particular aspect of my data filtering, working with a degrading sine wave, and l need to determine the max and min values of the wave. Have had a few ideas.. one would be to sort the data values, and then determine through time interval at what point the values are equivalent of similar, another process might be to determine the initial max/min values and then crop the named ranged to that point and then re-detemine the max/min value of the remaining range, etc until the wave degrades to zero. :banghead:
If anyone can shed some light, please..thxks:cloud9: :cloud9: :cloud9:

p45cal
08-09-2011, 06:01 AM
If the data is a good sine wave without noise, then it's a cse of running down the data looking for values which:
have a lower value either side of them for the maxima
and those which have a value higher either side of them will be minima:
in B3:
=AND(A3>=A2,A3>=A4)
in C3:
=AND(A3<=A2,A3<=A4)
both copied down:
6395
I've conditionally formatted for TRUE, but you could filter the table.

altbeb
08-09-2011, 01:31 PM
Hi p45:

that might just do it :yes ..:beerchug: :cloud9: hey p45 thxks very much

regards

altbeb

altbeb
08-10-2011, 10:32 PM
Hi p45cal:

worked a treat.. again thxks very much:thumb :beerchug: