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Efficient Multiscale Sampling from Products of Gaussian Mixtures

Published 9 December 2003
Alexander Ihler, Erik B. Sudderth, William T. Freeman, Alan S. Willsky
Citations85

TL;DR

Two multi-scale samplers for sampling from a product of Gaussian mixtures are developed, a multiscale variant of previously proposed Monte Carlo techniques, with comparable theoretical guarantees but improved empirical convergence rates.

Abstract

The problem of approximating the product of several Gaussian mixture distributions arises in a number of contexts, including the nonparametric belief propagation (NBP) inference algorithm and the training of product of experts models. This paper develops two multiscale algorithms for sampling from a product of Gaussian mixtures, and compares their performance to existing methods. The first is a multiscale variant of previously proposed Monte Carlo techniques, with comparable theoretical guarantees but improved empirical convergence rates. The second makes use of approximate kernel density evaluation methods to construct a fast approximate sampler, which is guaranteed to sample points to within a tunable parameter # of their true probability. We compare both multiscale samplers on a set of computational examples motivated by NBP, demonstrating significant improvements over existing methods.

Keywords

Computer ScienceMathematics