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1-Visitor
February 8, 2016
Solved

How to do FFT/continouse Fourier analysis for a tabulated data (time vs amplitude)?

  • February 8, 2016
  • 3 replies
  • 7696 views

Hi,

I want to do Fourier analysis of a signal which is available to me as a sampled data (sampling frequency is much higher than the signals frequency), and time & sampled data is tabulated in excel file. Consider that I do not have a formula which can define the signal  as a function of time.

Is it possible in Mathcad to do the Fourier analysis for this signal?

If yes,

how to do this?

Is there  any limitation in number of data points to perform FFT. ( Excel has limitation of 4096 data points.)

Please find the attached file as an example for signal to be analyzed .  

Thanks.

Manish Kumar

Best answer by RichardJ

See the attached worksheet.

3 replies

23-Emerald IV
February 8, 2016

Sure, mathcad can do that. See here for a recent post on FFT Can MathCAD do Discrete Fourier Transforms of a waveform?

But if you take the time to search this forum you will find lots of information on doing fft and their inverse with Mathcad.

Depending on the FFT function you choose (fft, FFT, cfft or CFFT) you are either limited by having the number of samples limited to a power of 2, or not. The other limitation is the maximum array size (over a million) and amount of memory in you PC.

Succes!

Luc

19-Tanzanite
February 8, 2016

The attached should help.

Alan

RichardJ19-TanzaniteAnswer
19-Tanzanite
February 8, 2016

See the attached worksheet.

mkumar-81-VisitorAuthor
1-Visitor
February 9, 2016

Thanks Richard. It seems to be working .