A non-homogeneous skew-Gaussian Bayesian spatial model

作者：Boojari Hossein; Khaledi Majid Jafari^*; Rivaz Firoozeh

来源：Statistical Methods and Applications, 2016, 25(1): 55-73.

DOI：10.1007/s10260-015-0331-x

• Non-homogeneous
• Skew-normal
• Fixed rank kriging
• Basis function
• Latent variable
• Multivariate spatial data
• Bayesian analysis

In spatial statistics, models are often constructed based on some common, but possible restrictive assumptions for the underlying spatial process, including Gaussianity as well as stationarity and isotropy. However, these assumptions are frequently violated in applied problems. In order to simultaneously handle skewness and non-homogeneity (i.e., non-stationarity and anisotropy), we develop the fixed rank kriging model through the use of skew-normal distribution for its non-spatial latent variables. Our approach to spatial modeling is easy to implement and also provides a great flexibility in adjusting to skewed and large datasets with heterogeneous correlation structures. We adopt a Bayesian framework for our analysis, and describe a simple MCMC algorithm for sampling from the posterior distribution of the model parameters and performing spatial prediction. Through a simulation study, we demonstrate that the proposed model could detect departures from normality and, for illustration, we analyze a synthetic dataset of CO measurements. Finally, to deal with multivariate spatial data showing some degree of skewness, a multivariate extension of the model is also provided.

• 出版日期2016-3