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Questions tagged [spectral]

145 questions
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Why do I have to use a gamma of 2.2 when using a JPEG picture?

During the rendering process, the texture file have a gamma of 2.2. But the plain color do not need this gamma correction, especially if the RGB values are from a spectral caracterisation. So, Why have I to use a gamma of 2.2 into my texture files…
Tofuw
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MATLAB: FFT with specified modes

Using MATLAB I want to implement some kind of a spectral method. The idea is as following (described for a example which is working). Dirichlet (and Neumann, and periodic) boundaries leads to eigenvalues in the fourier space of k=n*pi/L Projecting…
Sandman
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Spectral clustering with sklearn and a big affinity matrix

I am trying to use the spectral clustering method provided by scikit-learn to aggregate the rows of my dataset (which are only 16000). My issue arises after I precompute the affinity matrix (a 16000x16000 float matrix) which allocates 3 gigabyte…
rano
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Degree Matrix in Spectral Clustering

I am currently learning spectral clustering. We decomposite the Laplacian Matrix which calculated by L = D - W. W is the adjacent matrix. However, I have found a lot codes online like spectral clustering they directly calculate D by diag(sum(W)). I…
Exia
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How to create a sensible Hilbert Spectrum plot with R (computing environment)

I am using the EMD package for R. This package has a spectrogram function for displaying a Hilbert Spectrum (calculated with hilbertspec). The output however, is really vague and black-white. This function does not seem to have an option for…
Peter Smit
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Spectral Subtraction in Java - using JMathLib

i'm new to Android and DSP. i'm implementing the Spectral Subtraction algorithm thanks my goal is to use this algorithm over a phone call stream buffer i'm trying to figure how to implement this code from the Matlab implementation of Spectral…
user1363411
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Matlab, FFT and Centroid Frequency

I have taken the FFT in Matlab in this given way. X=fft(t); % Take Fourier Transform T=abs(X); % Take real parts of transform T=T(1:n/2); I'm interested in finding the centroid frequency of this plot. I understand that the centroid freuency is…
Abid
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Use spectral via javascript api returns empty result

I try to lint my open api spec with spectral using its javascript api but it always returns an empty array, even when my spec is definitely invalid. This is the Jest test I am using to test my rules: const myLinter =…
Tobias Neubert
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how to validate regex for open API using spectral rule

I am creating a custom rule for spectral for mapping the path and path parameters but having some difficulty with regex. I have the following rules: 1) URI MUST be in lowercase OR with combined words using the hyphen( - ). Aka…
user565
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How to force sneak_case in all request and response parameters in spectral

I'm tring to use spectral to make all the property names in request and response to match sneak_case name convention, but I am not able to get the syntax right. I have the following config file for spectral: extends: ["spectral:oas",…
Antonio Gamiz Delgado
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3D data with SUSI

I am trying to use SUSI on hyperspectral data, but I am getting errors. I am sure that I am the problem and not SUSI. import susi as su import spectral as sp import spectral.io.envi as envi import numpy as np import matplotlib.pyplot as plt import…
russj
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Plot Spectral Signatures - Hyperspectral images Python

I'm working with hyperspectral images of cactus, I'm interested in plotting the wavelength. I've been using Spectral https://www.spectralpython.net/graphics.html#spectrum-plots I have the image in ndarray (MxNxB = 600x1024x768) format and I can not…
Armayeestr
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Spectral Lint whole project (all YAML/JSON files) in IntelliJ

I am working on spectral linting tool to linting the API (YAML/JSON). I want to lint all the files (YAML/JSON) which are available in the project using IntelliJ. Please share the details to setup and process if anyone worked on Spectral Linting…
VEER SINGH
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OpenAPI Specification - Use of Discriminator and oneOf - Spectral listing

OpenAPI Discriminator using oneOf A minimal example of using a discriminator with an openApi spec and linting with Spectral. Error message: ~/git/openapi_discriminator/openapi/v1/api.yaml 22:23 error oas3-valid-media-example "example" property…
Behoove21
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Custom rule for application/problem+json using Stoplight Spectral CLI

I'm trying to make a custom rule based on the unkown-error-format that can be found here here. Using this Open API document as an example: openapi-generated.yaml openapi: 3.0.3 info: title: API version: 1.0.0 servers: - url:…
pedroddvale
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