Bagplots, boxplots and outlier detection for functional data

Rob J Hyndman, Han Lin Shang
(2008) In Dabo-Niang, S., and Ferraty, F. (eds), Functional and Operatorial Statistics, chap 31, 201-207

DOI

We propose some new tools for visualizing functional data and for identifying functional outliers. The proposed tools make use of robust principal component analysis, data depth and highest density regions. We compare the proposed outlier detection methods with the existing “functional depth” method, and show that our methods have better performance on identifying outliers in French male age-specific mortality data.