NONPARAMETRIC FUNCTIONAL DATA ANALYSIS THROUGH BAYESIAN DENSITY ESTIMATION

In many modern experimental settings, observations are obtained in the form of functions, and interest focuses on inferences on a collection of such functions. Some examples are conductivity-temperature-depth (CTD) data in oceanography, dose-response models in epidemiology and time-course microarray...

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Bibliographic Details
Main Authors: Abel Rodríguez, David B. Dunson, Alan E. Gelfand
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2007
Subjects:
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.64.2506
http://ftp.isds.duke.edu/WorkingPapers/07-07.pdf
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Summary:In many modern experimental settings, observations are obtained in the form of functions, and interest focuses on inferences on a collection of such functions. Some examples are conductivity-temperature-depth (CTD) data in oceanography, dose-response models in epidemiology and time-course microarray experiments in biology and medicine. In this paper we propose a hierarchical model that allows us to simultaneously estimate multiple curves nonparametrically by using dependent Dirichlet Process mixtures of Gaussians to characterize the joint distribution of predictors and outcomes. Func-tion estimates are then induced through the conditional distribution of the outcome given the predic-tors. The resulting approach allows for flexible estimation and clustering, while borrowing information across curves. We also show that the function estimates we obtain are consistent on the space of inte-grable functions. As an illustration, we consider an application to the analysis of CTD data in the north Atlantic.