Posted in 2014

Statistics and machine learning

  • 13 August 2014

Below are some introductory texts for probability, statistics, machine learning and statistical learning theory. They are sorted roughly according to difficulty, so you can find a book that is suitable for where you are and what you need.

A First Course in Probability (9th Edition)
Sheldon M. Ross
This book covers combinatorics and stuff. For undergraduates. Might be too easy.

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Boltzmann machines and hierarchical models

  • 02 August 2014

The restricted Boltzmann machine (RBM) is a key statistical model used in deep learning. They are special form of Boltzmann machines where the underlying graph is a bipartite graph. Personally, I am more interested in Boltzmann machines because they represent a class of discrete energy models where the energy is quadratic. The dynamics of the model bears a lot of resemblance to those of Hopfield networks and Ising models. As an aside, normal distributions are continuous energy models where the energy is quadratic and positive definite.

If the energy of the model is a polynomial of higher degree (e.g. cubic, quartic), then the model is hierarchical. They are a kind of graphical model where the underlying graph is a simplicial complex (a special type of hypergraph). Here are some slides and papers on hierachical models:

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