Fast Fourier Transform in excel

[lavster]

I really need your help - i can't work out how to do a FFT in excel. The main problem is I don't have a constant sampling rate - I recorded the time and then the corresponding magnitude of the wave. I have followed everything oneline but I can't seem to get anything to work as I can't fill the frequency column. Can someone help please? I've attached my spreadsheet. The first column is the time, the second is the data taken at that time and the other stuff is using the Data Analysis tool in excel

Thanks

 

[Greg Bernhardt]

Did you try these steps?
http://www.techgenie.com/technology/how-to-do-a-fast-fourier-transform-fft-in-microsoft-excel/

It appears you need to plug in an equation for the frequency column.

 

[lavster]

thats what I was following. It only works for a constant sampling rate...

 

[Andre]

It's a bit of work but if you look at the delta t's it's always a multitude of 0.5E-8.

So expand the rows until all are equally separated by a t= 0.5E-8 and intrapolate.

Edit: see attached for starters