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Questions tagged [frequency-analysis]

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Audio files Android

I wanted to know if there is a way to process an audio file via Android. in practice I would upload the audio file and change the bpm for example how does the software audacity. thank you
Davide Torchia
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Accurate frequency estimation with short time series data - maximum entropy methods or Yule Walker AR method?

I am using the Lomb-Scargle code to estimate some frequencies in a short time-series, the time series is shown in the first image. The results of the Lomb-Scargle analysis are shown in the second, and I have zoomed in on a prominent peak at about 2…
user2653752
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FFT of tidal data - problems identifying Mf component in MATLAB

I am running an FFT in MATLAB of some tidal data. I am using the FFT function: y = tide_data Fs = 12*24; % Sampling frequency (number of samples per day) L = numel(y(:,ii)); % Length of time series NFFT = 2^nextpow2(L); % Next power of 2 from length…
user2653752
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How to get the sample frequency axis in R?

Im trying to plot a time series data in the frequency domain in R. I have a csv file with columns/signals x, y and z. The Signal has been sampled with frequency of 50 Hz. Length of the data are N=651. I did the following steps for the column/signal…
Benaissa Tahiti
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Count sequences of letters in a string - C++

I'm working on a simple substitution-cipher decoder. I'm using frequency analysis to decrypt the ciphertext. Just looking at the frequency of unique letter isn't enough. I need to look at the occurrences of 2-letter sequences (maybe 3-letter…
m.lapeyre
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Matlab fftshift not working correctly

I am trying to plot the frequency spectrum of a sinewave with frequency 77.5 kHz and amplitude 2. Only the zero-point is not correct, it is shifted to the left. My code: f1=77.5e3; % frequency of the sinewave a1=2; % amplitude of the sinewave Fs…
B_s
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Irrklang Frequency Spectrum with C++

As someone with absolutely no experience in how audio works, I'm want to make a real-time frequency spectrum with audio that I'm currently playing through irrklang. Ideally, I would like to have db values of different frequencies in an array of…
Kevin Pei
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Keeping tagged word within FreqDist in Python with NLTK package

I would like to differentiate words that spell the SAME way but have different genres in my FreqDist count. For instance in the sentence: The dog seemed to dog the turtle. I would like to have one count for the 'dog' as a noun, one for the 'dog'…
Felix
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Fast Fourier Transform of Frequency Analysis in Labview

I'm currently measuring the signal from 3 direction vibration sensor. I wan to convert my signal to a FFT form to determine the frequency analysis of it. Anyone got idea how I do it in Labview?
Royal DeviLz
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how to count frequency count in triple nested loop

I am trying to determine the frequency count of a triple nested loop. for i = 1 to n do for j = 1 to i do for k = i to j do x = x + 1 I know that the statement x = x + 1 will not get executed until i attains the value of…
Tarang Hirani
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Capture Sound from Mic/Headphone and trigger action at perticular frequency

I am using .NET 3.5. I need to Capture Sound from Mic/Headphone and trigger action at particular (not exact) frequency (Need to perform some action when player hits ball with stick while playing golf). So, 1. How to capture sound from…
Chintan Shah
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Detection of peaks in the frequency spectrum without using FFTs MATLAB

Assuming I have a signal x(t), would it be possible for me to detect the peak in the frequency spectrum (that is, the frequency with the highest energy content) without using FFTs ? *PS - I saw something in Wavelet Decomposition called scale2freq().…
Roy2511
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How to get the update frequency of websites

I need to build a web service that analyzises SEO. The service will show how often the site was updated. I need to figure out how to get the posted date or update frequency from the HTML of the website. For example on …
Fame th
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Seeing frequency information off microphone

Alright, I wanna program onto a micro-controller a way to basically handle song waves. So I need to be able to detect certain frequency ranges; When the bass is hitting (say 80-120Hz range reaches a certain amplitude), and then blink a…
John
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Interpreting unicode data read out from a mp3 file object

I am reading a mp3 file object using python. f = open("/home/user/temp.mp3", "r") My ultimate aim is to extract the amplitudes and frequencies as functions of time. I am referring to the wiki page,…
Manoj
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