
"Statistical Rethinking: A Bayesian Course with Examples in R and Stan builds readers’ knowledge of and confidence in statistical modeling. Reflecting the need for even minor programming in today’s model-based statistics, the book pushes readers to perform step-by-step calculations that are usually automated. This unique computational approach ensures that readers understand enough of the details to make reasonable choices and interpretations in their own modeling work. The text presents generalized linear multilevel models from a Bayesian perspective, relying on a simple logical interpretation of Bayesian probability and maximum entropy. It covers from the basics of regression to multilevel models. The author also discusses measurement error, missing data, and Gaussian process models for spatial and network autocorrelation." --Publisher's website.
This is widely regarded as the most accessible intro textbook to Bayesian statistics.
I like Statistical Rethinking, but unfortunately the solver was very slow and I didn't end up using it much - not the author's fault, it's probably my computer that's way too old.
So how does it change shape? Well this part is actually something I don't fully grasp myself yet. But I can sketch a crude bayesian interpretation, which is how I think of it. Not completely correct but works as a placeholder until I fully work out the math of updating the parameters.
Basically, from a bayesian perspective we can condition the joint distribution of function outputs as a likelihood conditioned on the kernel parameters theta: p(f(x1), f(x2), ... | theta).
Then we can derive the posterior distribution over theta p(theta | f(x1), f(x2), ...) like so:
p(theta | f(x1), f(x2), ...) ≈ p(f(x1), f(x2), ... | theta) p(theta).
So we fit the theta parameters based on how well it fits the observed data we feed our bayesian model.
FWIW, I recommend chapter 14 of Richard McElreath's Statistical Rethinking for a better introduction of GPs. This article kind of glosses over a lot of the intuition and introductory concepts that you need to really grok it.
Think Stats: Probability and Statistics for Programmers (https://allendowney.github.io/ThinkStats/)
Computer Age Statistical Inference (https://hastie.su.domains/CASI/)
Statistical Rethinking (https://xcelab.net/rm/)
An Introduction to Statistical Learning (https://www.statlearning.com/)
Obviously maths is going to be involved to do the subject justice. These recommendations are more about applied statistics, but that's the foundation. From there it is a small transition to statistical process control.