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arXiv 1702.01987stat.AP
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变换权重的重要性抽样

Importance sampling with transformed weights

Manuel A. Vázquez, Joaquín Míguez

摘要:

重要性抽样(IS)方法是许多基于蒙特卡罗技术的核心。IS允许通过从不同于目标的建议(或重要性)分布中抽取样本并计算说明这两个分布之间的差异的重要性权重(IWs)来近似目标概率分布。IS方案的主要缺点是IWs的退化,这显著降低了方法的效率。最近有人提出使用变换的IWs(TIWs),以减轻人口蒙特卡罗,这是一个迭代版本的IS的背景下的退化问题。然而,这种技术的标准IS的有效性还有待研究。在这封信中,我们数值评估的性能时,使用TIWs的IS,并表明,该方法可以达到鲁棒性的重量退化由于偏差/方差权衡。

英文摘要:

The importance sampling (IS) method lies at the core of many Monte Carlo-based techniques. IS allows the approximation of a target probability distribution by drawing samples from a proposal (or importance) distribution, different from the target, and computing importance weights (IWs) that account for the discrepancy between these two distributions. The main drawback of IS schemes is the degeneracy of the IWs, which significantly reduces the efficiency of the method. It has been recently proposed to use transformed IWs (TIWs) to alleviate the degeneracy problem in the context of Population Monte Carlo, which is an iterative version of IS. However, the effectiveness of this technique for standard IS is yet to be investigated. In this letter we numerically assess the performance of IS when using TIWs, and show that the method can attain robustness to weight degeneracy thanks to a bias/variance trade-off.

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