CASC 2005 Poster ================ TITLE ----- Apollonius Circle Conflict AUTHORS ------- Ioannis Z. Emiris - National University of Athens George M. Tzoumas - National University of Athens ABSTRACT -------- Computation of the Voronoi diagram of a set of ellipses in the plane involves high degree polynomial equations. We have solved efficiently several predicates, but the main operation appears to be the determination of the relative position of a query ellipse with respect to the Apollonius circle of three given ellipses. We avoid computations with high degree algebraic numbers, which are often costly and inefficient operations. Instead, we propose a subdivision-based full-precision algorithm that exploits the geometric characteristics of the problem.