论文标题
通过收缩先验控制非高斯流程的灵活性
Controlling the flexibility of non-Gaussian processes through shrinkage priors
论文作者
论文摘要
正常的逆高斯(Nig)和广义的不对称拉普拉斯(GAL)分布可以看作是高斯分布的偏斜和半高尾的扩展。然后,由这些更灵活的噪声分布驱动的模型被视为更简单的高斯模型的灵活扩展。推论程序倾向于高估数据中的非高斯性程度,因此,我们建议通过在推论框架中添加明智的先验来控制这些非高斯模型的灵活性,从而使模型符合高斯性。在我们推出明智的先验的冒险中,我们还提出了非高斯模型的新直觉参数化,并讨论了如何以$ stan $有效地实施它们。这些方法是针对包括空间Matérn字段,时间序列自回旋模型以及航空数据同时自动回归模型的通用非高斯模型类别的。通过模拟研究和地统计学应用来说明结果,在该研究中,惩罚模型复杂性的先验会导致更强大的估计,并优先考虑高斯模型,同时,如果数据中有足够的证据,则可以允许非高斯性。
The normal inverse Gaussian (NIG) and generalized asymmetric Laplace (GAL) distributions can be seen as skewed and semi-heavy-tailed extensions of the Gaussian distribution. Models driven by these more flexible noise distributions are then regarded as flexible extensions of simpler Gaussian models. Inferential procedures tend to overestimate the degree of non-Gaussianity in the data and therefore we propose controlling the flexibility of these non-Gaussian models by adding sensible priors in the inferential framework that contract the model towards Gaussianity. In our venture to derive sensible priors, we also propose a new intuitive parameterization of the non-Gaussian models and discuss how to implement them efficiently in $Stan$. The methods are derived for a generic class of non-Gaussian models that include spatial Matérn fields, autoregressive models for time series, and simultaneous autoregressive models for aerial data. The results are illustrated with a simulation study and geostatistics application, where priors that penalize model complexity were shown to lead to more robust estimation and give preference to the Gaussian model, while at the same time allowing for non-Gaussianity if there is sufficient evidence in the data.