AKA digital signal processing (DSP). A signal is an information-carrying wave, but in the digital sense, a 'signal' refers to either received or transmitted streams/blocks of data, commonly representing real-world quantities such as audio levels, luminosity, pressure etc over time or distance. ...
3
votes
0answers
31 views
2D disease problem modeling [closed]
I'm modeling a disease problem where each individual in a 2D landscape has a transmissibility described by a (radial basis) kernel function. My goal is to convolve the kernel with the population ...
8
votes
3answers
99 views
Speeding up spectrum analysis
I'm trying to speed up this code that loops over an entire spectrum range. It's using a Raspberry Pi, and a rtl-sdr dongle that covers up to around 1.7 GHz. My goal is to be sweep over that spectrum ...
5
votes
1answer
130 views
Comparing FFTs to deduplicate IVR recordings
I've got a Python script that traverses two file trees, checking all .wav files for duplication.
I'm still an undergrad, and have never worked with audio before. I'm not entirely sure this is going ...
2
votes
0answers
213 views
fftshift implementation for OpenCV
I'm trying to implement fftshift from matlab for OpenCV. Can you please review the correctness of my algorithm? Have I missed something? Also, is there a better and faster way to do it?
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6
votes
1answer
334 views
5
votes
1answer
184 views
Beat detection algorithm implementation
What is the quality of the code I've written? Is it easy to read or is it a low-quality piece of code? Also, is there any way I can improve the algorithm itself (beside changing C parameters)?
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2
votes
0answers
114 views
Smoothing matrix for visual representation
I recently started playing around with R and am currently trying to plot GPS data points onto a perspective plot. I have a script that works and I get my desired results out of it and it works ok for ...
2
votes
0answers
35 views
One-dimensional convolution using Data.Vector
As part of some code I've written, I needed to perform a 1-D convolution. This convolution ends up happening quite often, so I wanted to optimise it (in some way other than using a FFT, though I could ...
12
votes
2answers
321 views
Find binary sequences with low peak sidelobe level of autocorrelation function
I would like to find all binary sequences from the specified range, which has low peak sidelobe level of its autocorrelation function.
Here is the solution (this is simplified version of the real ...
3
votes
1answer
264 views
Python implementation of multidimensional power spectral density with Welch method
I have done my best to write Welch method implementation for python for multidimensional time series and still in the case of one dimensional time series I am getting inconsistent response compared to ...
6
votes
2answers
108 views
Performance of speech enhancement code for Android app
I wrote a speech enhancement code for an Android App. The algorithm runs on 256 size frames of voice samples. On my PC the code runs per about 5ms per frame, while on my Nexsus 5 it more like 50ms per ...
2
votes
0answers
143 views
Cythonized version of FDCT (fast discrete cosine transform) function, ported from Java
This is my Cython code for an FDCT function (invoked here):
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5
votes
2answers
128 views
FIR filters in C
I wrote 2 filters in C for the Altera DE2 Nios II FPGA, one floating-point and one fixed-point. I've verified that they perform correctly and now I wonder if you can give examples for improvement or ...
3
votes
1answer
180 views
Calculate FFT from windowed time-based signal
I have a time-based signal (Raw signal) sampled at 6 MHz and need to analyze it in freq. domain.
I'm learning DSP and this is very first time I work with DSP. Could you please help to check if this ...
3
votes
1answer
172 views
Reading a data file for performing a FFT
I'm a bit concerned about function usage. There are so many different libraries/possible ways to do something that I'm not sure if the way I'm working at the moment is reasonable, or what I could ...
4
votes
1answer
282 views
Onset detection using FFT
I am using this onset source code and this fft file to try to perform onset detection. Currently the code is working, but as my DSP and C skills are subpar I could use some advice on how to improve ...
6
votes
1answer
189 views
Computing a Discrete Cosine Transform matrix
I'm learning Haskell and I needed to work with discrete cosine transform matrices, so I made a program that generates text (usable in WolframAlpha) containing the generated matrix.
The elements of ...
3
votes
1answer
91 views
Zero crossings from a 1D signal
I'm trying to get the peaks/zero crossings from a basic 1D signal and am not sure if my naive/basic approach is correct:
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2
votes
1answer
622 views
Fourier transformation for review
Could someone be kind enough to review the Fourier transformation below please? I'm especially interested in going about unit testing the code (I don't really know where to begin, beyond applying the ...
2
votes
1answer
9k views
Matlab code demonstrating use of fft (Fast Fourier Transform)
I posted the following Matlab script in response to a question on Signal Processing. Here is the questions with my answer.
I am looking for comments on how to make this code more instructive for the ...
