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

 

[alphy]

for reaching out for help with your FFT in Excel. It sounds like you are on the right track by using the Data Analysis tool, but the issue of a variable sampling rate can definitely complicate things.

One solution could be to interpolate your data to create a uniform sampling rate, and then perform the FFT on the interpolated data. Alternatively, you could try using a different software specifically designed for FFT analysis, such as MATLAB or Python. These programs have built-in functions for handling variable sampling rates and conducting FFT calculations.

If you would like to continue using Excel, I recommend looking into the "Interpolate" function to create a uniform sampling rate, or seeking out online tutorials or forums for assistance with your specific issue. Best of luck with your analysis!