Professor Jean-Michel Poggi, from the University Paris, France, will present the Department of Statistical Science seminar with a talk entitled, "Spatial CART Classification Trees".

Abstract: Based on links between partitions induced by CART classification trees and marked point processes, we propose a spatial variant of CART method, called SpatCART, focusing on the two populations case. While usual CART tree considers marginal distribution of the response variable at each node, we propose to take into account the spatial location of the observations. We introduce a dissimilarity index based on Ripley's intertype K-function quantifying the interaction between two populations. This index used for the growing step of the CART strategy, leads to a heterogeneity function consistent with the original CART algorithm. The proposed procedure is implemented, illustrated on classical examples and compared to direct competitors. SpatCART is finally applied to a tropical forest example.

This is a joint work with Avner Bar-Hen (CNAM, Paris, France) and Servane Gey (MAP5, Univ. Paris Descartes, Paris, France)