Statistica Sinica 14(2004), 789-808

THE FUNCTIONAL DATA ANALYSIS VIEW OF

LONGITUDINAL DATA

Xin Zhao$^1$, J. S. Marron$^2$ and Martin T. Wells$^1$

$^1$Cornell University and $^2$University of North Carolina

Abstract: Longitudinal data can be viewed as a type of functional data. The functional viewpoint is not typical for most analysts of longitudinal data, but provides a route for powerful new insights. The potential of this approach is demonstrated through an analysis of periodicities in a microarray gene expression data set.

Key words and phrases: Classification, Fourier subspace, functional data analysis, longitudinal data, SiZer analysis, time-course micro-array experiments, yeast cell cycle.