Questions tagged [spectral]
145 questions
0
votes
1 answer
Receiving MATLAB Error Regarding Function Arguments
When running my MATLAB script below, I keep getting an error that states:
Error using spa (Line 147)
The value of the window
size must be an integer greater than 2.
Error in "projectName" G = spa(xFunction2, x)
I've tried putting in multiple…
Andrew T
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0
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1 answer
Spectral (SPy) label legend
I would like to put a legend below the image drawn by the spectral module. I wonder if there is an builtin way to do this? I haven't found anything about making legends in the spectral API.
Here is an example
img = np.array([111, 112, 113, 121, 122,…
Davor Josipovic
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0
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0 answers
Python - list of list of single items for spectral python
I'm new around here but I've been using answers for a long time and they're always helpful, but I'm not finding this one.
I'm working with spectral python for some data manipulation, and I'm vastly changing my input data. In fact, I'm creating new…
0
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2 answers
Unrealistic Eigenvalues in networkx
Good afternoon,
A relatively well known mathematical theorem in graph theory (see the Introduction of "Bipartite and Neighborhood Graphs and the Spectrum of the Normalized Graph Laplace Operator" by Bauer and Jost) states that the spectrum of the…
user5994810
0
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0 answers
Matlab IFFT in 3-dimension
I am trying to use Matlab's ifftn in 3-dimensions to get solution in physical space. In particular I am trying to use ifftn on 1/k^2. The analytical solution to that in physical space is 1/(4*pi*r). However I am not recovering that. Please note: $r…
Brato
- 113
- 3
0
votes
1 answer
I need to spectral clustering for two donuts shape dataset.(Matlab)
I have tried hours but I cannot find solution.
I have "two Donuts" Data sample (variable "X")
you can download file below link
donut dataset(rings.mat)
which spreads to 2D shape like below image
First 250pts are located inside donuts and last 750…
MJ.Shin
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- 9
0
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2 answers
import error: no module named spectral
I have already installed all the SPy dependencies and trying to import the spectral module in ipython version3.0 and getting this error : no module named spectral. what could possibly be wrong?
RachJain
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0
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1 answer
spectrum examples don't work?
I downloaded the marple data from here:
http://www.ece.rice.edu/dsp/courses/elec532/DATA/
I then tried to run examples from here:
http://thomas-cokelaer.info/software/spectrum/html/user/ref_param.html#module-burg
At first, I thought maybe the data…
Ivan
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- 134
0
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Spectrum Derivative in MATLAB, the end point problem
I am trying to take the derivative of the a spectrum with 125 bands using the following lines:
dW=diff(wavelength);
dR=diff(data);
df=dR./dW;
problem is in the next step i want to compare it with original spectrum numerically and also visually by…
Ress
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0
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Spectral embedding - spectral clustering
I'm trying to perform spectral embedding/clustering using Normalized Cuts. I wrote the following code but I have stuck to a logical bottleneck. What do I have to do after clustering the eigenvectors? I don't know how to form the clusters on my…
azal
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0
votes
1 answer
implementation of Lomb-Scargle periodogram
from matlab official site , Lomb-Scargle periodogram is defined as
http://www.mathworks.com/help/signal/ref/plomb.html#lomb
suppose we have some random signal let say
x=rand(1,1000);
average of this signal can be easily implemented…
user466534
0
votes
1 answer
Computing the Spectral Centroid (SC) in MATLAB
I hope to inspect the spectral centroid (SC) in my WAV file.
I am using the following MATLAB code to do so:
function C = SpectralCentroid2(signal,windowLength, step, fs)
% function C = SpectralCentroid(signal,windowLength, step, fs)
%
% This…
Westporch
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votes
1 answer
Create multivariate similarity graph
I am trying to learn and implement spectral clustering on a multivariate dataset in R. I have 9 independent variables and 1 dependent variable which is binary.
As a first step to spectral clustering, I am required to create a graph from the given…
Patthebug
- 4,647
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0
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1 answer
gain spectral structure from given periodic components
i have following following model
clear all;
A1=24;
A2=23;
A3=23;
A4=23;
A5=10;
f1=23;
f2=43;
f3= 10;
f4=16;
phi=2*pi*(rand(1,4)-0.5);
t=0:0.01:2.93;
x=rand([1,length(t)]);
…
user466534
0
votes
1 answer
Performing a 4 loop (?) anova in R
I am undertaking spectral analysis on vegetation and am looking into seeing which is the most significant wavelength in order to undertake some remote sensing.
I have 2000 wavelengths however, so I need to find a way of running an ANOVA quickly and…
user3270281
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