eliminating noise from data

[jvallee]

I am trying to take the noise out of some strain gage readings. I figur
that there is a way to create an if-then statement that will perfor
the following. IF the current point differs from the previous point b
more than some specified value, THEN make the current point equal t
the previous point.

This will help my curves to be cleaner, and more defined.

Please help, I cannot figure out any formula to work.

Thanks in advace, because you guys are good, and have came throug
before for me.

Jeff

:confused

 

[kkknie]

The formula for that would be:

=IF(ABS(A2-A1)>1.1,A1,A2)

i.e. if the absolute difference is > 1.1, use the old value, otherwise,
use the new one.

You could also think about using a filter using a percentage of the old
and a percentage of the new. Something like:

=A1*0.8 + A2*(1-0.8)

where 0.8 could be a cell reference.

Another option is to take an average of the last few points without the
highest and lowest:

=(Sum(A1:A5)-Max(A1:A5)-Min(A1:A5))/3

Just a few ways to smooth data that I use.

K