Digital signal processing of sound, video or other single or multidimensional data
18
votes
3answers
2k views
Computing and plotting a spectrogram in Mathematica
How can I compute and plot the spectrogram of a signal/time series/data in Mathematica? I have a WAV file, sampled at 44100 samples/second and I want to generate a spectrogram of that data. Something ...
17
votes
3answers
1k views
Can one find the beat of a tune with Fourier analysis?
I'm trying to find out if it's possible to find the beat of a tune by Fourier analysis with Mathematica. I'm taking a 44.1 kHz sample sound and hoping that I might get a nice peak for a frequency ...
17
votes
2answers
391 views
Implementing continuous phase/Arg function
In MATLAB there's a function called phase that is just like our Listable friend Arg, but ...
21
votes
7answers
610 views
Graphical representation of a moving sound source
Some explanation since I have got a specific and another more open-ended question:
I used two microphones in a 90° arrangement (see picture below) to capture sound from a source moving around the room ...
27
votes
4answers
579 views
Filtering beat-to-beat heart rate data
From an experiment, I have a dataset of beat-to-beat heart rate data: a list of the time between each heart beat in [ms].
The data is measured using an infrared optic sensor at the finger tip. The ...
16
votes
5answers
2k views
How to find the phase difference of two sampled sine waves?
I'm trying to measure a phase difference between two Sine functions I've acquired with a computer. I'm uploading one of the .txt files with the data I'm working with here: txt file. To remove the ...
15
votes
1answer
1k views
How to demodulate an FM signal in continuous-time?
I'm not sure if this is a math or Mathematica question, but I'm posting it here because I'm interested in possible Mathematica tools/functions to solve the problem.
I'm stuck. I want to simulate ...
12
votes
4answers
1k views
Numerical Fourier transform of a complicated function
Say I have a function $f(x)$ that is given explicitly in its functional form, and I want to find its Fourier transform[1]. If $f$ is too complicated to have an analytic expression for $\hat f(k)$, how ...
12
votes
3answers
2k views
Implementing discrete and continuous Hilbert transforms
What is an efficient and accurate Mathematica implementation of the Hilbert transform, for both continuous and especially discretely sampled functions?
This transform relates phase and amplitude in ...
10
votes
3answers
444 views
What is Mathematica's equivalent to MATLAB's filter function?
The MATLAB code
filter(0.5,[1, -0.5], [1:10])
is equivalent to
Rest@FoldList[(#1 + #2)/2. &, 0, Range[10]]
I don't ...
6
votes
3answers
455 views
How to properly plot a response of a transfer function in Mathematica?
I'm trying to display the output response of a transfer function in Mathematica with and without a compensator. The problem is very strange: while the transfer function compensate is showing well, the ...
2
votes
1answer
205 views
Obsolete Signal Processing functions
I need some tools to detect the fundamental frequency and pitch of a sound. I Googled for "pitch detect" and found some .nb files that do these tasks, but all the files are in Mathematica 3.0 format. ...
