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arXiv 1402.0694stat.COstat.ML
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状态空间模型的粒子Metropolis调整Langevin算法

Particle Metropolis adjusted Langevin algorithms for state space models

Chris Nemeth, Paul Fearnhead

摘要:

粒子MCMC是一类可用于分析状态空间模型的算法。它们使用MCMC移动来更新模型的参数,并使用粒子滤波器来为状态空间模型的路径提供值。当前默认使用随机游动Metropolis更新参数值。我们表明,它是可以使用的粒子滤波器的输出信息,以获得更好的建议分布的参数。特别地,可以从粒子滤波器的每次运行获得对数后验的梯度的估计,并且在Langevin型提议内使用这些估计。我们建议使用Nemeth等人(2013)最近的计算效率高的方法来获得这样的估计。我们的经验表明,对于各种状态空间模型,这个建议是更有效的比标准的随机游动大都会建议方面:减少后验样本的自相关性,减少老化的MCMC采样器的时间和增加后验样本之间的平方跳跃距离。

英文摘要:

Particle MCMC is a class of algorithms that can be used to analyse state-space models. They use MCMC moves to update the parameters of the models, and particle filters to propose values for the path of the state-space model. Currently the default is to use random walk Metropolis to update the parameter values. We show that it is possible to use information from the output of the particle filter to obtain better proposal distributions for the parameters. In particular it is possible to obtain estimates of the gradient of the log posterior from each run of the particle filter, and use these estimates within a Langevin-type proposal. We propose using the recent computationally efficient approach of Nemeth et al. (2013) for obtaining such estimates. We show empirically that for a variety of state-space models this proposal is more efficient than the standard random walk Metropolis proposal in terms of: reducing autocorrelation of the posterior samples, reducing the burn-in time of the MCMC sampler and increasing the squared jump distance between posterior samples.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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