Haiku (inspired by Diane Souvaine, 3/18/06)

Three points to the left

of me and four points to the

right of me: depth three.

Half space depth inside

convex gon divides the plane

into small, odd pieces.

Call closed simplices

deep if x can rest in all

but a small fraction.

Convex hull peeling

depth with respect to data

points to inner strength.

Classification

so robust against outliers

rests when points don't roll.