In this paper we present an empirical Bayes method for flexible and efficient Independent Component Analysis (ICA). The method is flexible with respect to choice of source prior, dimensionality and positivity of the mixing matrix, and structure of the noise covariance matrix. The efficiency is ensured using parameter optimizers which are more advanced than the expectation maximization (EM) algorithm, but still easy to implement. These optimizers are the overrelaxed adaptive EM algorithm and the easy gradient recipe. The required expectations over the source posterior are estimated with accurate mean field methods: variational and the expectation consistent framework.We demonstrate the usefulness of the approach with the publicly available Matlab toolbox icaMF.
Flexible and Efficient Implementations of Bayesian Independent Component Analysis
AbstractIn this paper we present an empirical Bayes method for flexible and efficient Independent Component Analysis (ICA). The method is flexible with respect to choice of source prior, dimensionality and constraints of the mixing matrix (positivity), and structure of the noise covariance matrix. The efficiency is ensured using parameter optimizers which are more advanced than the expectation maximization (EM) algorithm, but still easy to implement. These optimizers are the overrelaxed adaptive EM algorithm and the easy gradient recipe. The required expectations over the source posterior are estimated with mean field methods: variational and the expectation consistent (EC) framework. We describe the derivation of the EC framework for ICA in detail and give empirical results demonstrating the improved performance. We demonstrate the usefulness of the approach with the publicly available Matlab toolbox icaMF.