Linked Questions
44 questions linked to/from What do the X and Y axis stand for in the Fourier transform domain?
3
votes
1answer
53 views
How does the Fourier transform take its input?
I'm using the Fourier command and I'm wondering how does it take its imput. I know that it takes a list of numbers representing a function of time and it gives back a list of numbers representing a ...
3
votes
1answer
4k views
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,...
3
votes
1answer
387 views
Fourier Transform accelerogram seismic
I have a seismic accelerogram. I tried to apply the Fourier Transform to interpolate function, but dosn't work.
So, i applied the ...
2
votes
1answer
175 views
Discrete Fourier transformation from ASCII (for noob)
I am not familiar with Mathematica (I am a physicist programming in Fortran) and my knowledge of it is very limited, unfortunately.
I would like to perform the Fourier trasform of a lightcurve which ...
2
votes
1answer
591 views
2
votes
1answer
107 views
Using ''Module' and 'Table' to Plot 'Fourier'
I'm trying to make a function that outputs a plot given a particular parameter, whilst using the Mathematica functions Module, Fourier, and Table. This is what I've come up with thus far.
...
1
vote
1answer
78 views
Fast method for numerical integral (Fouriertransform?)
I want to numerically compute following integral (as fast as possible):
\begin{equation}
f(x) = \left| \int e^{ \mathrm{i} p x / 2} f(p) \ \mathrm{d}p\right|^2 ,
\end{equation}
where $f(p)$ is given ...
1
vote
1answer
99 views
Finding frequency of oscillation of an particle by Fourier analysis of the trajectory [duplicate]
I am trying to find the resonant frequency of a particle by Fourier analysis of the trajectory.
Here is the data file.
...
1
vote
1answer
388 views
Get frequency axis in Fourier transform (and save them)
I am trying to get the Fourier transform of a light-curve (with an even number of points, 300, and equally spaced in time, 6.9 seconds) and my problem is to get the frequency on the x-axis.
I can ...
1
vote
1answer
510 views
DFT: why are frequencies mirrored around the frequency axis?
I want to apply Mathematica's DFT procedure, Fourier[], to a Gaussian. Why a Gaussian? Because I know the analytical result.
So I define
...
0
votes
1answer
62 views
How can I make an FFT in Mathematica using data from a file? [closed]
I need to calculate the seismic moment of an earthquake data, but I don't know how the FFT is applied in some data, my data is a plain text that I must import it to Mathematica
...
0
votes
1answer
92 views
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:
...
0
votes
1answer
228 views
Discrete fourier transform and convolution — scaling factor?
I am trying to convolve a square wave (a diffraction grating phgrating with slits size \[CapitalLambda]) with a point spread ...
0
votes
1answer
117 views
Identifying the three frequencies using fourier transform
The following simple function has clearly three frequency components:
...
0
votes
1answer
95 views
How to fit one function into the form of another?
I have a slightly complicated periodic function of one variable t, say g[t].
I want to do a least squares fit of that function ...