# Questions tagged [kernel]

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28 questions
0answers
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### Sum of two kernel is also a kernel, how can we prove that? [duplicate]

Suppose that k(·, ·) and k 0 (·, ·) are kernels. Prove that l(·, ·) where l(x, y) = k(x, y) + k0 (x, y) is also a kernel. I am having trouble proving this, can you help?
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### Linear separation in higher dimension

I am having a problem comprehending with the relation of kernel, weight and linear separation. I have a case where I am given a kernel k1. that has a corresponding mapping phi1. And we know that ...
0answers
18 views

### What kind of kernel is used by statsmodels.nonparametric.kernel_regression.KernelReg?

I am doing multivariate nonparametric kernel regression using the Python function as mentioned in the title. The documentation can be found here: https://www.statsmodels.org/stable/generated/...
1answer
19 views

### Intuition behind the length-scale of the Rational Quadratic Kernel

What is the meaning of the length-scale in a rational quadratic? \begin{equation} k_{\textrm{RQ}}(t, t') = \sigma^2 \left( 1 + \frac{(t - t')^2}{2 \alpha \ell^2} \right)^{-\alpha} \label{eq:...
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### Can SVM with Gaussian RBF kernel separate all kinds of data theoretically?

Gaussian is well known because its corresponding feature mapping is to infinite dimension. So with finite number of training data, is that the case that we can achieve zero training error with some ...
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### Kernel Density Estimation for non-parametric

I'm writing an R function to get the fitted values of the kernel density estimate. For that I use the computational formula of summation of {n-1 h-1 K{(x - Xi)/h}} where n is the number of ...
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22 views

### The role of Fisher information matrix in Fisher kernel

I read the original paper proposed the Fisher kernel. The Fisher kernel is defined as $K(X_i,X_j) \propto U_{X_i}I^{-1}U_{X_j}$, where $U_X$ is the Fisher schore and $I$ is the Fisher information ...
0answers
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### Kernlab, user-defined kernel on chosen variables [closed]

I want to make a user-defined kernel with different variables in the kernel and combine them. Does anyone know if this is possible with kernlab or what is wrong with my code? I use these packages: <...
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### Why does the DCGAN output degrade with an increase in the kernel size?

Thank you for the explanation on the kernel size. I have been experimenting with the sample Generative Adversarial Network (GAN) code from the book on Deep learning with Python by François Chollet, ...
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### Is a kernel density estimate meaningful if > 25% of my data are duplicates?

The title pretty much says it all. I have data that consists of 80 samples but there are always at least four samples that have exactly the same value. I want to assess, whether the data is unimodal. ...