Finite Fourier Transforms (help Wanted)

[pellicle]

Hi

 

I'm having a bit of trouble marrying concept and execution.

 

My understanding is that I can (somehow) use FFT to determine any underlying frequencies in a time series of data. Some of the documents I've read have even suggested that this is done for instance to determine the frequencies related to sunspot activity.

 

So, if I have a set of data which I've gathered daily (well not every day there are gaps) and I would like to see if there is any frequency cycles involved just how would I easily do this?

 

Say, in Excel but if needed in C

 

 

Thanks

 

:-)

[ErlyRisa]

That's hard stuff...I'd go to school for that, or buy a book.

 

Excel -- FFT is one of those "high power" things - ie. The lighter weight the program the better...

 

Maple I think is the better way to go... and you'll enjoy doing math with that alot more.

www.maplesoft.com/products/maple/‎

or i think you can buy "engines" for excel to make your spreadsheets fly.

 

I actually would like to be able to learn how todo this type of stuff myself: It's used everywhere, it's just a matter of understanding how to parameterise what it is your looking at. Like your example of sunspot activity  (Sunspot, @ date, size of, direction of, bla bla), then applying FFT for that, just note FFT is for cyclical activity (ie, first used on oscilloscopes for finding parts of waves that are/wanted/unwanted - I think), but is now utilised on bigger scales like on Humans (ecosystems), at the stock market: made alot of people kill themselves - all bets started to become predicatable.