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Questions tagged [spectrum]

The frequency domain of a wave-like function.

Spectrum refers to the full range of all frequencies of electromagnetic radiation. Spectrum has since been applied by analogy to topics outside of electromagnetic radiation. For a complete discussion, see the Wikipedia Spectrum article

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How to plot the bandwidth that contains 99% power of a signal?

I would like to estimates the width of the frequency band that contains 99% of the power of my signal (sound waveform), the upper and lower bounds of the band, and the power in the band. I also would like to plot the bandwidth on the power spectrum…
user3406207
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Android accelerometer frequency domain analysis FFT

I want to create an android app for vibrations analysis using embedded accelerometer, would you suggest an easy solution/library to get a frequency spectrum out of the x,y,z accelerations?
avafab
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SciPy periodogram for finite-length signal

I input a finite-length signal to the periodogram function and get the power spectrum density. However, since the signal has a finite length, the power spectrum density I get has a sinc-like lobes. Is there any implantation in SciPy, which can be…
Ji Chen
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Real-time spectrum analyzer with API

I'm looking for a C or C++ API that will give me real-time spectrum analysis of a waveform on Windows. I'm not entirely sure how large a sample window it should need to determine frequency content, but the smaller the better. For example, if it can…
bobobobo
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Mathcad to Matlab - white noise, fft and NPS testing

I'm trying to write simple function in Matlab to calculate and plot Noise Power Spectrum (NPS). First off I wanted to test if the algorithm I got from my teacher was fine and all. Here it is (it was made in mathcad) So i tried to pretty much…
Warner
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Spectrum analyzer for .raw 16bit linear files

I have to make a spectrum analyzer for .raw 16-bit linear files. I had a look at this but it works only with .wav files. Do you know any tutorial/example that can help me create a spectrum analyzer for .raw files?
dominic
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Spectrum Colorpicker unable to return "background-color: transparent"

I'm creating a simple HTML editor where users have the chance to edit pre-made html blocks. One of this blocks has a default background color and I'm using Spectrum to give users the chance to change it. Since there's already a default background…
nienn
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Java - Analizing Spectrum of a song - output on certain peaks

I am relatively new to Java, and I have never dealt with sound before, but as a school project we need to code a program (Major project for the year) and I need to process a song, and output certain words on certain frequency hitmarkers (so if it…
user3241507
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nls when the data is a convoluted spectra (variable number of variables)

I have some spectrum data that looks like one of the multiplets when is plotted: http://journals.prous.com/journals/dof/19982303/html/df230301/images/keiferf3.gif How it is seen in the image, all the peaks are realy close among each other, so I…
user3032330
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Time Series from spectrum

I am having a samll problem while converting a spectrum to a time series. I have read many article sand I htink I am applying the right procedure but I do not get the right results. Could you help to find the error? I have a time series like: When…
JPV
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Plot received powers with gnuplot

I'd like to plot the received powers over different wireless channels. For each channel, I have three values, and I want to plot them stacked. Actually, this is my script: set boxwidth 0.6 relative set ylabel "dBm" set xlabel "Channel" set style…
lbedogni
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How can I implement semi-automatic peak-picking

I am working on photoluminescence temperature series. I hence have several intensity Vs energy (eV) spectra, taken at different temperatures. My issue is that the signal processing/peak finding packages I have found so far (Peaks, hyperSpec,…
Thibaud Ruelle
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Finding peaks in 2D matrix in java

I've spent a few days searching a for solution to my problem. I'm having a problem in finding peaks in one large matrix (approx. 1400 x 2700). I need to find the main peak and two smaller peaks - in the other words the three largest peaks in the…
viktor.radovic
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How to draw a frequency spectrum from a Fourier transform

I want to plot the frequency spectrum of a music file (like they do for example in Audacity). Hence I want the frequency in Hertz on the x-axis and the amplitude (or desibel) on the y-axis. I devide the song (about 20 million samples) into blocks of…
goocreations
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Recognising an individual guitar chord from an audio sample

I realise there are a fair few questions on here already with regard to chord detection algorithms; however, most of these seem to be relating more to interpreting songs into sets of chords or chord transcription. My problem ought to be a lot…
nihilo90
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