Cone Depth and the Center Vertex Theorem
Presented at The Fall Workshop in in Computational Geometry, October 31, 2008
We generalize the Tukey depth to use cones instead of halfspaces. We prove a generalization of the Center Point Theorem that for $S\subset \reals^d$, there is a vertex $s\in S$, with depth at least $\frac{n}{d+1}$ for cones of half-angle $45^\circ$. This gives a notion of data depth for which an approximate median can always be found among the original set. We present a simple algorithm for computing an approximate center vertex.