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arXiv 1802.06151stat.CO
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时空高斯Cox过程的可分级推断

Scalable Inference for Space-Time Gaussian Cox Processes

Shinichiro Shirota, Sudipto Banerjee

摘要:

对数高斯Cox过程是一种灵活而流行的点模式模型,用于捕获点模式的空间和时空依赖性。模型拟合需要通过在感兴趣的域上离散化来实现随机积分的近似。对于精细尺度离散化,基于马尔可夫链蒙特卡罗的推断在计算上是繁重的,因为对于与潜在高斯变量相关联的高维协方差阵,矩阵分解和存储(例如Cholesky)的成本。本文通过结合两个最新的发展来解决这些计算瓶颈:(i)已经为时空高斯考克斯过程提出的数据增强策略,其基于精确的贝叶斯推断并且不需要用于无限维积分的细网格近似,以及(ii)最近开发的稀疏诱导高斯过程族,称为最近邻高斯过程,以避免昂贵的矩阵计算。我们的推理是在完全基于模型的贝叶斯范式内进行的,并且不会牺牲传统对数高斯Cox过程的丰富性。我们将我们的方法应用于旧金山的犯罪事件数据,并研究强度表面的恢复。

英文摘要:

The log-Gaussian Cox process is a flexible and popular class of point pattern models for capturing spatial and space-time dependence for point patterns. Model fitting requires approximation of stochastic integrals which is implemented through discretization over the domain of interest. With fine scale discretization, inference based on Markov chain Monte Carlo is computationally burdensome because of the cost of matrix decompositions and storage, such as the Cholesky, for high dimensional covariance matrices associated with latent Gaussian variables. This article addresses these computational bottlenecks by combining two recent developments: (i) a data augmentation strategy that has been proposed for space-time Gaussian Cox processes that is based on exact Bayesian inference and does not require fine grid approximations for infinite dimensional integrals, and (ii) a recently developed family of sparsity-inducing Gaussian processes, called nearest-neighbor Gaussian processes, to avoid expensive matrix computations. Our inference is delivered within the fully model-based Bayesian paradigm and does not sacrifice the richness of traditional log-Gaussian Cox processes. We apply our method to crime event data in San Francisco and investigate the recovery of the intensity surface.

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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