Abstract
We present a new family of approximation techniques for probabilistic graphical models,
based on the use of graphical preconditioners developed in the scientific computing
literature. Our framework yields rigorous upper and lower bounds on event probabilities
and the log partition function of undirected graphical models, using non-iterative
procedures that have low time complexity. As in mean field approaches, the approximations
are built upon tractable subgraphs; however, we recast the problem of optimizing
the tractable distribution parameters and approximate inference in terms of the well-studied
linear systems problem of obtaining a good matrix preconditioner. Experiments
are presented that compare the new approximation schemes to variational methods.
|
Pradeep Ravikumar Last modified: Mon Nov 28 00:20:49 EST 2005