Contents

About

This project explores selected aspects of Gaussian processes (GPs) by implementing them (a.k.a. “learning by hacking”).[1]

Content

GP intro

Unless stated otherwise, we use the Gaussian radial basis function (a.k.a. squared exponential) as covariance (“kernel”) function

\[\kappa(\ve x_i, \ve x_j) = \exp\left(-\frac{\lVert\ve x_i - \ve x_j\rVert_2^2}{2\,\ell^2}\right)\]

Notation:

  • RBF kernel length scale parameter: \(\ell\) = length_scale (as in sklearn)

  • likelihood variance \(\sigma_n^2\) (a.k.a. “noise level”) in GPs, regularization parameter \(\lambda\) in KRR: \(\eta\) = noise_level (as in sklearn)

  • posterior predictive variance: \(\sigma^2\)

Resources

[DLvdW20]

Marc Peter Deisenroth, Yicheng Luo, and Mark van der Wilk. A practical guide to gaussian processes. 2020. URL: https://infallible-thompson-49de36.netlify.app/ (visited on 2020-12-03).

[GKD19]

Jochen Görtler, Rebecca Kehlbeck, and Oliver Deussen. A Visual Exploration of Gaussian Processes. 2019. URL: https://distill.pub/2019/visual-exploration-gaussian-processes (visited on 2022-11-22), doi:10.23915/distill.00017.

[KHSS18]

Motonobu Kanagawa, Philipp Hennig, Dino Sejdinovic, and Bharath K. Sriperumbudur. Gaussian Processes and Kernel Methods: A Review on Connections and Equivalences. 2018. URL: http://arxiv.org/abs/1807.02582, arXiv:1807.02582.

[Mur22]

Kevin P. Murphy. Probabilistic Machine Learning: Advanced Topics (draft version). MIT Press, 2022. URL: https://probml.github.io/pml-book/book2.html.

[RW06]

Carl Edward Rasmussen and Christopher K. I. Williams. Gaussian Processes for Machine Learning. MIT Press, 2006. ISBN ISBN-10 0-262-18253-X. URL: http://www.gaussianprocess.org/gpml.

Citing

The source code and this book are licensed under the BSD 3-Clause License. If you re-use material from this work or just like to cite it, then either use this BibTeX entry

@Online{schmerler_GPPlayground,
  author   = {Steve Schmerler},
  title    = {GP Playground},
  url      = {https://github.com/elcorto/gp_playground},
  subtitle = {Explore selected topics related to Gaussian processes},
  doi      = {10.5281/zenodo.7439202},
}

or the DOI 10.5281/zenodo.7439202.