Stack Overflow
Stack Overflow

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

389 questions
1
vote
0 answers

Bass.dll just Spectrum data C#

I am trying to create a game based on beat and spectrum detection. I am currently stuck on that my function returns not quite what i want, beacose the array is not fully assigned. The last element which is filled is wrong and i don't know why. The…
J1and1
  • 920
  • 3
  • 12
  • 25
1
vote
1 answer

Understanding mel-scaled spectrogram for a simple sine wave

I generate a simple sine wave with a frequency of 100 and calculate an FFT to check that the obtained frequency is correct. Then I calculate melspectrogram but do not understand what its output means? where do I see the frequency 100 in this output?…
codeDom
  • 1,623
  • 18
  • 54
1
vote
1 answer

Coherence values do not agree when trying to calculate using different methods

I'm trying to see if I can obtain identical coherence values for two signals when computing them two different ways: Method 1: I first compute the cross-correlation and the two auto-correlations. Then I take the DFT of the results to obtain the…
fishbacp
  • 1,123
  • 3
  • 14
  • 29
1
vote
2 answers

When to use Redshift Spectrum for your Redshift data warehouse

I am still new to Redshift service and quite confused of when to use or what data to put into Spectrum. Suppose I have star schema data warehouse on Redshift, should I put fact table or dim table into Spectrum(external tables from s3) for storage…
Ryan
  • 71
  • 3
1
vote
0 answers

reproduce frequency peaks using spectrum analyzer matlab

I have captured RF data and am using dsp.SpectrumAnalyzer to find the frequency peaks of the signal. But the peaks are not reproducible. They are changed whenever I run the code again. My data is the same, so I should get the same results each…
Baig
  • 11
  • 3
1
vote
0 answers

Python looping over fits datacube to fit spectra

I have a fits datacube in Python where I need to fit the spectra of each pixel in the cube. My code for fitting just one spectrum works great, but for some reason I can't figure out how to translate that into fitting each pixel (100 pixels total for…
Lacey A-P
  • 11
  • 1
1
vote
1 answer

How to smooth spectrum cycling in CSS when skipping dull colors

I need to cycle through bright colors using CSS just like how your RGB mouse and keyboards are and so far I have a solution sort of working using HSL. It does however include some really dark colors that I'm trying to skip. But obviously when you…
bassicplays
  • 328
  • 1
  • 7
  • 21
1
vote
1 answer

python signal.scipy.welch for complex input returns frequency indices which are not ordered negative to positive

My aim is to plot the PSD of a complex vector x. I calculated the spectrum estimation using scipy.welch (version 1.4.1): f, Px = scipy.signal.welch(**x**, return_onesided=False, detrend=False) and then plotted: plt.plot(f,…
Idnv
  • 13
  • 5
1
vote
1 answer

how to generate histogram from a bin?

I have some data as numpy arrays x, y, v as shown in the code below. This is actually dummy data for velocity (v) of dust particles in a x-y plane. I have binned my data into 4 bins and for each bin I have calculated mean of entries in each bin and…
Jerome
  • 49
  • 8
1
vote
1 answer

AudioKit v5 using multiple Taps

I'd like to be able to get amplitude and spectrum data from my AudioPlayer, but since each Node can only have one tap, I'm unsure how to make this work in AudioKit 5 player = AudioPlayer(file: fileToPlay)! fftTap = FFTTap(player, bufferSize: 4096,…
PaperEdge
  • 83
  • 6
1
vote
1 answer

Mean spectra over multiple pixels from datacube

I have a fits datacube with galactic longitude, latitude and velocity in the 3 axis. To extract the spectrum from the datacube at a particular pixel value of longitude and latitude, I use the function cube[:, 1935, 1407].quicklook() plt.show() and…
Lidia
  • 27
  • 5
1
vote
0 answers

Power spectrum using librosa python

I need to obtain an FFT spectrum and Power spectrum in dB for a .wav file with 2s of data. I need to obtain an "averaged power in dB" for the complete time period. I use the following code : # Read 2s of data from wav file y, sr =…
Shan
  • 11
  • 5
1
vote
1 answer

Finding RMS noise in a spectra

I have an intensity v/s velocity spectrum and my aim is to find the RMS noise in the spectrum excluding the channels where the peak is present. So, after some research, I came to know that RMS noise is the same as the standard deviation of the…
Lidia
  • 27
  • 5
1
vote
2 answers

How do I convert mapped data to dictionary, where each XY coordinate contains a spectrum?

I have a 2D map where each pixel contains a spectrum. I want to convert the data from this format: X Y Wave Intensity -34727.180000 -4204.820000 1.484622 139.193512 -34727.180000 -4204.820000 1.484043 …
T Walker
  • 330
  • 1
  • 3
  • 12
1
vote
1 answer

"pspectrum" function in python

I have used 'pspectrum' in MATLAB and I must admit that it is a very powerful function that yields in a very neat power spectrum. Below shows the the power spectrum once plotted using 'pspectrum' and the other using 'fft' method…
Khalid
  • 13
  • 6
1 2 3
…
25 26