Bayesian models have become very popular over the last years in several fields such as signal processing, statistics, and machine learning. Bayesian inference requires the approximation of complicated integrals involving posterior distributions. For this purpose, Monte Carlo (MC) methods, such as Markov Chain Monte Carlo and importance sampling algorithms, are often employed. In this work, we introduce the theory and practice of a Compressed MC (C-MC) scheme to compress the statistical information contained in a set of random samples. In its basic version, C-MC is strictly related to the stratification technique, a well-known method used for variance reduction purposes. Deterministic C-MC schemes are also presented, which provide very good performance. The compression problem is strictly related to the moment matching approach applied in different filtering techniques, usually called as Gaussian quadrature rules or sigma-point methods. C-MC can be employed in a distributed Bayesian inference framework when cheap and fast communications with a central processor are required. Furthermore, C-MC is useful within particle filtering and adaptive IS algorithms, as shown by three novel schemes introduced in this work. Six numerical results confirm the benefits of the introduced schemes, outperforming the corresponding benchmark methods. A related code is also provided.
翻译:在过去的几年里,贝叶斯模型在信号处理、统计和机器学习等若干领域变得非常流行。贝叶斯推断要求近似包含后传分布的复杂整体体。为此,常常采用蒙特卡洛(MC)方法,如Markov Caincle Monte Carlo和重要抽样算法。在这项工作中,我们引入压缩的MC(C-MC)办法的理论和实践,以压缩一组随机样本中所含的统计信息。在其基本版本中,C-MC严格与分层技术(一种众所周知的用于减少差异的方法)有关。还介绍了确定性C-MC办法,这些办法提供非常良好的性能。压缩问题与不同过滤技术(通常称为高斯二次曲线规则或光点方法)中应用的时间匹配方法密切相关。当需要与中央处理器进行廉价和快速的通信时,C-MC可以用于分布式的Bayesian推理框架。C-MC在粒子过滤和适应性IS算法中非常有用,这在三种新的计算方法中也证明了采用。