Analysis of local influence in geostatistics using Student's t-distribution

Abstract

This article aims to estimate parameters of spatial variability with Student's t-distribution by the EM algorithm and present the study of local influence by means of two methods known as likelihood displacement and Q-displacement of likelihood, both using Student's t-distribution with fixed degrees of freedom (ν). The results showed that both methods are effective in the identification of influential points.

Keywords:

• spatial variability
• Q-displacement of likelihood
• EM algorithm
• diagnostics

Acknowledgements

We would like to thank CAPES (Coordination for the Improvement of Higher Education Personnel), CNPq (National Council for Scientific and Technological Development) and Fundação Araucária, Brazil, for their financial support. The third author also acknowledges financial support from Proyecto FONDECYT 1110318, Chile.