Multivariate Functional Outlier Detection using the FastMUOD Indices

We present definitions and properties of the fast massive unsupervised outlier detection (FastMUOD) indices, used for outlier detection (OD) in functional data. FastMUOD detects outliers by computing, for each curve, an amplitude, magnitude and shape index meant to target the corresponding types of...

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Bibliographic Details
Authors: Ojo, Oluwasegun|||0000-0001-9629-6990, Fernández Anta, Antonio, Genton, Marc G., Lillo, Rosa Elvira
Format: article
Publication Date:2023
Country:España
Institution:IMDEA Networks Institute
Repository:IMDEA Networks Institute Digital Repository
Language:English
OAI Identifier:oai:dspace.networks.imdea.org:20.500.12761/1679
Online Access:https://hdl.handle.net/20.500.12761/1679
https://dx.doi.org/10.1002/sta4.567
Access Level:Open access
Keyword:FastMUOD, functional data, functional outlier detection, multivariate functional data, outlier classification, video data
Description
Summary:We present definitions and properties of the fast massive unsupervised outlier detection (FastMUOD) indices, used for outlier detection (OD) in functional data. FastMUOD detects outliers by computing, for each curve, an amplitude, magnitude and shape index meant to target the corresponding types of outliers. Some methods adapting FastMUOD to outlier detection in multivariate functional data are then proposed. These include applying FastMUOD on the components of the multivariate data and using random projections. Moreover, these techniques are tested on various simulated and real multivariate functional datasets. Compared with the state of the art in multivariate functional OD, the use of random projections showed the most effective results with similar, and in some cases improved, OD performance.