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3
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1
answer
157
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How to compute the power spectral density of a vector-valued process without mirroring the autocorrelation function?
I'm simulating a 2D Ornstein-Uhlenbeck process (Langevin equation for velocity), and I'm interested in computing the power spectral density (PSD) of the vector-valued velocity process.
Following the ...
0
votes
0
answers
129
views
Power spectrum and power spectral density in Matlab
I'm currently trying to analyze the spectrum of a prbs signal in order to better desing inputs for my experiments. However, I have some confusion so far. On one side, we can use Matlab's cpsd function ...
0
votes
0
answers
45
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Design differential equation FOR FIR filter
I need to design a difference equation that will be used as an FIR type filter that will block the frequencies 20 to 40 Hz, and its spectral resolution is Df=0.3 and Dt=2mSec.
I need to write down an ...
0
votes
0
answers
66
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Welch periodogram for turbulence spectrum
I am trying to compute the turbulence density spectrum with a Welch periodogram. The results seem good but I do not manage to find the fluctuation of streamwise velocity that I am supposed to find ...
0
votes
0
answers
589
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Amplitude in Frequency domain not matching time domain signal after FFT in python. Explanation?
I am trying to create a Power spectral density function in python that outputs the amplitude spectral density and cumulative power spectral density graphs. I am using scipy.fft to compute the FFT of ...
0
votes
1
answer
858
views
Proper use of window parameter for Welch power spectral density (scipy)?
I am trying to calculate the Welch power spectral density over specific frequency bands for EEG signal processing ($\delta$ (0–4 Hz), $\theta$ (4–8 Hz), $\alpha$ (8–13 Hz), $\beta$ (13–30 Hz), $\...
0
votes
0
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383
views
Calculation of the power-law distribution (and exponent)
Aim: My aim is the calculation and display of a power-law distribution.
Input to Phyton: The input files for Python provided by me are 1-column .txt files. Each .txt file has a column of numeric ...
2
votes
0
answers
430
views
High pass filter with specific cut-off frequency
The situation
I am trying to apply a high pass filter to a black&white image to enhance the texture by keeping the high frequencies. The goal is to filter from a specific frequency value obtained ...
0
votes
1
answer
710
views
Power Spectrum Analysis for a very large set of data
I have a voltage signal that I am trying to denoise. The signal comes in very large files (524288 cells). When I take the whole file and make n equal to length of data set, I get two extremely large ...
0
votes
0
answers
226
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Using spectrum function to find peaks with same intervals
I have to analyze data and find instances that have higher values repeating through same intervals. Example:
I am trying to use spectrum function but it gives me weird result.
Here is my example data,...
0
votes
1
answer
753
views
Rotate PSD plot in Python by 90 degrees
I have generated a Power Spectral Density (PSD) plot using the command
plt.psd(x,512,fs)
I am attempting to duplicate this plot from a paper:
I am able to get the spectrogram and the PSD graph. I ...
1
vote
0
answers
625
views
How to open/read an ENVI file in R
I'm new at using GIS with R and I'm trying to open an ENVI file containing hyperspectral data following the suggestions from this post R how to read ENVI .hdr-file?, but I don't seem to be able to do ...
0
votes
1
answer
2k
views
How to get the amplitude spectrum function from the PSD or ASD?
I am sorry in advance for a bit clumsy question, but I am really stucked in the simple, but not trivial problem of finding the amplitude spectrum function from the given PSD or ASD.
So, what I have ...
0
votes
1
answer
153
views
I am unable to get the psd range in R package psd to extend to a frequency of 1.5Hz
I have a timeseries for which I need PSD values using R. The data was sampled at non uniform intervals but I did a spline interpolation with the predict command to interpolate readings at exactly 0....
1
vote
1
answer
977
views
Scikit Spectral Clustering fails to classify concentric circles
Here is some code to set up the clustering problem:
import numpy as np
import matplotlib.pyplot as plt
# KMeans
# # Class=2
# Center(2.5,2.5), r1 = 2, r2 = 1
X1 = np.zeros(500*4)
X2 = np.zeros(500*4)
...