Unoriented $Theta$-Maxima in the Plane: Complexity and Algorithms
David Avis, Bryan Beresford‐Smith, Luc Devroye, Hossam A. ElGindy, Eric Guévremont, Ferrán Hurtado, Binhai Zhu · SIAM Journal on Computing · 1998
We introduce the unoriented $\Theta$-maximum as a new criterion for describing the shape of a set of planar points. We present efficient algorithms for computing the unoriented $\Theta$-maximum of a set of planar points. We also propose a simple linear expected time algorithm for computing the unoriented $\Theta$-maximum of a set of planar points when $\Theta=\pi/2$.