In this paper we study the separability in the plane by two criteria: double-wedge separability and Θ-separability. We give an O(N logN)-time optimal algorithm for computing all the vertices of separating double wedges of two disjoint sets of objects (points, segments, polygons and circles) and an O((N/Θ0) logN)-time algorithm for computing a nearly-straight minimal Θ-polygonal chain separating...
