I think you are looking for an integral (not FFt) so you can get average
temperatures. The integral is the area under the curve. You can do a
rectangular approximation to get the answer.

For each time period create a rectangle with a triangle on top. the area of
the rectangle is the time period times height of the first point. The area
of the tirangle is (1/2 * time period) * absolute (2nd temperature - 1st
temperature).

Average temperature is total area calcualted above divided by the total time.

"maqqusz" wrote:


"Joel"

Can anybody tell me how I make a FFT-Transformation in Excel?
I have never used an AddIn before and so I don't know how to
do ist. My Values [2] I want to transform are yearly Temperatures
from 1980 to 2006, so the Imaginary-value may be zeros.

How do I do such a Transformation. There are 127 Values
so if I add one unknown more it should be possible.

[1] http://home.arcor.de/maqqusz/wetterr...temperatur.png
[2] http://home.arcor.de/maqqusz/wetterr...Temperatur.xls
[3] http://home.arcor.de/maqqusz/wetterr...Temperatur.txt


Not usre why you want a FFT. I would format you trnad line (right click
trand line) and make it a polynomial of 6th order to get a more precise
trandline.

So I will explain it to you:

The sunspots from the Sun have 11y long "cycles". With the FFT I want to
detect them in the global temperature.

So can anybody help me to do this with this Data in Excel?

Markus