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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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comparing two frequency spectra

I'm trying to compare two frequency spectra but I am confused over a number of points. One device samples at 40 Hz the other at 100 Hz and so I'm not sure if I need to take this into account. Anyway I have produced frequency spectra from both…
branny12000
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Financial time series: python Matplotlib "specgram" y-axis displaying Period instead of Frequency

python Matplotlib's "specgram" display of a heatmap showing frequency (y-axis) vs. time (x-axis) is useful for time series analysis, but I would like to have the y-axis displayed in terms of Period (= 1/frequency), rather than frequency. I am still…
TonyMorland
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ChemoSpec can't find getManyCsv function

I'm trying to create the Spectra object (.RData), just like suggested on ChemoSpec.pdf (see the code below), and I get an error message like this: "could not find getManyCsv function" How can I fix it? Any suggestion is appreciated. I have R version…
awel.llwyd
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Units for Matlab PSD

Im new to matlab and as part of my university assignment,im supposed to draw up these signals on matlab.and i have some problems regarding the units of the psd plots. 1)j=0:1/100:1; %time index z=sin(2*pi*5*j); %sine wave…
Vihanga Gamage
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Save spectrum of DFT using OpenCV

I am using Visual Studio 2013 and OpenCV library. I display discrete Fourier transform and it works well. I'd like to save the displayed image which is the spectrum, but the saved one is black even when I use JPEG quality=100. #include…
user3554447
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Matlab: how to find fundamental frequency from list of energy peaks

In a spectrogram, I have a set of harmonic frequencies (peaks in the spectrum) for a given time frame: 5215 3008.1 2428.1 2214.9 1630.2 1315 997.01 881.39 779.04 667.47 554.21 445.77 336.39 237.69 124.6 If I do -diff(ans), I get the differences…
Lewistrick
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How to convert a speech spectrum to time domain

I am doing speech analysis. I recorded the sound for 5 seconds. Applied Hamming window, DC offsetting and normalising and using fft took the spectrum. I want to hear how much the sound has changed. So is there a way to convert the fft back to time…
Naveen Cherian
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Python spectrum package installation

I am trying to do some spectral analysis in python and am having trouble installing the spectrum package using easy install. I get the following errors? Anyone have any similar trouble? C:\Windows\system32>easy_install spectrum Searching for…
jmcneill
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FFT shows (wierd) sine wave in spectrum

I don't know if this is a programming or math question, but I have put together some short examples of FFT. I load in a 440hz wave and add some sine waves on top, but for some reason, the spectrum has a 'wave' that I don't understand. The spectrum,…
Mads Y
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AS3 positioning audio spectrum/visuallizer

I've been looking for code for positioning the spectrum into the center of the flash screen, but unable to find it. I'm using the code below: SoundMixer.computeSpectrum(liveBytes, false, 0); var g:Graphics = this.graphics; g.clear(); g.lineStyle(10,…
putoshop
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spectrum - input value not changing in firefox

I try use spectrum in a form on an input field with id id_color. However, selecting a color does not change the value of id_color. What am I doing wrong? [edit1] Seems like the key to the problem is the option showButtons: false. I would rather like…
speendo
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Spectum Colorpicker input[type='text'] not working when IE is switched to 10 and older versions

I'm using Spectrum Colorpicker, which is pretty awesome javascript plugin. It works perfectly with Chrome and FF and IE 11. But when I switch to IE 10 and older, The input='text' elements stop showing their beautiful skin. the header:
Nerdar
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find actual frequency in case of normalized frequency

.suppose that we have some sample y = 31.2241 -5.9830 22.6058 -2.2309 -42.8272 29.2850 -6.2652 20.8502 -2.4639 -44.7525 30.1104 -6.0180 21.4476 -1.5089 -45.1826 29.2744 and somehow i know that it it…
user466534
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Matlab HRV frequency domain analysis using pburg and pwelch function

i am doing HRV analysis and i've ran into a problem. I have sets of RR interval (about 100-160 in each) for example RR=[726 679 687 655 719 632 1071 978] etc, there are about 100-160 values in each RR. Now i need to do frequency analysis using…
user3131046
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Firefox unaccesible spectrum cause sound object crash

I'm having a issue with SoundManager2 API. I use whileplaying parameter to call a function where I obtain spectrum of the sound (Created in the API) and create a wave. The problem resides when I open another flash object with a soundSpectrum the API…
Marcos Eusebi
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