论文标题
使用自适应再生过程采样
Sampling using Adaptive Regenerative Processes
论文作者
论文摘要
通过固定再生分布$μ$再生以特定再生速率$κ$从固定再生分布$κ$重新生成的马尔可夫进程中,以目标分布$π$作为其不变分布,以其不变的分布,以此来丰富布朗运动。出于蒙特卡洛的推论,实施这种方案需要首先选择再生分配$μ$,其次要计算特定常数$ c $。在实践中,这两个任务都非常困难。我们引入了一种通过向其添加点质量来调整再生分布的方法。这使得可以使用尽可能少的再生来模拟该过程,并消除了找到所述恒定$ c $的需求。此外,固定$μ$的选择取代了初始再生分布的选择,这要少得多。我们建立了这一产生的自我增强过程的融合,并探索了其从许多目标分布进行采样方面的有效性。示例表明,适应再生分配电荷避免固定再生分布的不良选择,并可以减少蒙特卡洛估计的利益期望的误差,尤其是在偏斜$π$的情况下。
Enriching Brownian motion with regenerations from a fixed regeneration distribution $μ$ at a particular regeneration rate $κ$ results in a Markov process that has a target distribution $π$ as its invariant distribution. For the purpose of Monte Carlo inference, implementing such a scheme requires firstly selection of regeneration distribution $μ$, and secondly computation of a specific constant $C$. Both of these tasks can be very difficult in practice for good performance. We introduce a method for adapting the regeneration distribution, by adding point masses to it. This allows the process to be simulated with as few regenerations as possible and obviates the need to find said constant $C$. Moreover, the choice of fixed $μ$ is replaced with the choice of the initial regeneration distribution, which is considerably less difficult. We establish convergence of this resulting self-reinforcing process and explore its effectiveness at sampling from a number of target distributions. The examples show that adapting the regeneration distribution guards against poor choices of fixed regeneration distribution and can reduce the error of Monte Carlo estimates of expectations of interest, especially when $π$ is skewed.