Davy Paindaveine (ULB): An excursion through statistical depth
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Europe/Brussels
CYCL 01 (Marc de Hemptinne)
CYCL 01
Marc de Hemptinne
chemin du Cyclotron 2
Description
Statistical depth aims at measuring centrality of any given
location in the d-dimensional Euclidean space with respect to
probability distributions over this space. For empirical distributions,
depth provides (i) a deepest point, that usually can be seen as a
multivariate median, and (ii) a center-outward ordering of the
observations. Depth may therefore be considered as a concept of
multivariate ranks. In this lecture, we will introduce the main concepts
of depth, including Tukey's halfspace depth and Liu's simplicial depth.
We will present some well-known properties and discuss Serfling's
axiomatic approach. We will then briefly describe some inferential
applications of depth. If time permits, the strong relation between
depth and multivariate quantiles will be examined, and depth will be
extended from (vector-valued) location parameters to (matrix-valued)
dispersion ones.