Lecture Notes: Factor graphs and belief propagation
Marc Toussaint · 2008
A graphical model is nothing but an illustration of an equation. This equation determins how a functional over multiple variables factorizes. We are mostly interested in functionals that represent a multivariate probability distribution – but graphical models and the related methods could be applied on any functional. Here are some basic examples for equations concerning the factorization of a functional P over variables X1:4 and their graphical notation: