I have some data that contains some noise, then good data then noise again. I
need to know how to perform a calculation on the good data while ignoring the
noise. The ammont of the noise/bad data is variable, so I need to be able to
vary the start and end of the formula.

To simplify say I have the DATA 30,20,39,2,23,1,2,3,4,5,6,7,8,9,10,32,23,43
in a columb, the data I want is 1-10 and ignoring the rest of the results.
Then I want to process the processed data to produce a Y=Mx+C formula
(LINEST). The data might have 2 noise numbers at the start, or 10 noise
number that need ignoring (I do this by IF greater than 0.05 or negative "
"). If I set LINEST to go from cell 1 to 100 the ignored data results in
#VALUE as " " even though blank is classed as text not numerical.

Does anyone have a way of processing this data?



The data come in a colum which I process to another colum to take out the
noise with the function IF difference between cell above and below greater
then 0.05, or negative then " ". On the processed data I perform an Array
function LINEST to produce a linear representation of the data which I want
to perform on all the good data, but currently I have to set it to start at
cell 20 and finish at cell 700. If there is noise present after cell 20
LINEST displays #VALUE as " " is classed as a text entry.