Linked Questions

0 votes
1 answer

Discrete Fourier Transform: help on how to convert x axis in to the frequency when I have a set of data samples [duplicate]

I have a huge data set (400000 sample) and when I plot them ListLinePlot[Au4, PlotRange -> {All, All}] I used the following code to Fourier transform it <...
ravi3's user avatar
  • 1
0 votes
1 answer

Using Fourier to get the numerical FT of a Gaussian [duplicate]

I've been trying to find the FT of a more complicated function, but it seems my method is wrong. To check, I tried to calculate the FT of a Gaussian numerically. This is what I did: ...
123infinity's user avatar
0 votes
0 answers

Help with Frequency Identification with Fourier? [duplicate]

Note: This question has been marked as a duplicate of What do the X and Y axis stand for in the Fourier transform domain?. While the answer will likely have an overlap, so the question should be ...
user3769181's user avatar
0 votes
0 answers

Frequencies for Fourier coefficients [duplicate]

I have been given the task of calculating the frequencies to which the fourier coefficients correspond. So my input is a discrete signal [1,4,0,1], which gives me <...
greedsin's user avatar
  • 101
0 votes
0 answers

Getting frequency domain data from time domain using Fourier transformation [duplicate]

I have a dataset following cosine function [e.g. cos(200t)] in time domain. In frequency domain two sharp lines should appear at -200 and +200. I have to do Fourier transform (or Fast Fourier ...
P Pyne's user avatar
  • 453
23 votes
6 answers

How do you find the frequency and amplitude from Fourier?

Edit This is a popular question with several answers. This edit organises the answers and gives links. Fourier just gives y values (ordinates) if you wish to read off frequencies and amplitudes you ...
Hugh's user avatar
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23 votes
3 answers

How to make Fourier behave like FourierTransform?

I'm not very experienced with Fourier Transforms, so there may be something inherently wrong with attempting to do this, but how can I make the discrete Fourier behave like the continuous ...
EmpireJones's user avatar
22 votes
4 answers

How to calculate the Fourier Transform of a Gaussian pulse with a nonlinear chirp: Cos[ t + Exp[t^2] ]?

I have an optical pulse in time domain: Exp[-t^2] Cos[50 t - Exp[-2 t^2] 8 π]. The figure of this formula is I hope to calculate the Fourier Transform of this ...
user14634's user avatar
  • 771
16 votes
2 answers

Does Mathematica implement the fast Fourier transform?

Is there a fast Fourier transform in Mathematica? Although looking in the help I could not find one. I am looking to implement the equivalent of fft in MATLAB.
500's user avatar
  • 5,579
7 votes
3 answers

extracting phase from sinusoidal data

I am dealing with data which are essentially are sinusoidal with various degrees of noise. I have an interest in extracting the phase of the data and rather than simply fitting a sine wave, I would ...
alex's user avatar
  • 1,438
5 votes
2 answers

Using Mathematica to take Fourier transform of data

i'm trying to use Mathematica to take a discrete Fourier transform of 68 data points (0 to 67) to perform further analysis. My data points, when plotted, look like this: Pretty straightforward. Now, ...
amantonas's user avatar
10 votes
2 answers

Frequency of ticks in mechanical watches

I'm looking to find the frequency of a relatively large dataset (or a relatively short audio file) of a repeating sound, like so: Here are the original files, for those willing to play. :) eta2412 ...
DrMrstheMonarch's user avatar
8 votes
4 answers

Challenge: Computing the Fourier Series of a List Plot!

I have a bunch of data points (copied from Mathematica below), which I have 'ListPlotted' I would now like to compute the Fourier series of this function (after doing a Fourier transform I assume? Or ...
rdx's user avatar
  • 103
5 votes
1 answer

Differences between FFT and analytical Fourier Transform

In MATLAB, if I perform an FFT on a simple Gaussian spot with a phase grating: ...
user12800's user avatar
10 votes
1 answer

finding Frequency of Sinewave data using Fourier

CONTEXT I read 5 different related posts but I do not understand how to interpret mathematica's output for my situation. ...
Conor's user avatar
  • 7,449

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