@article{2009-EnclosingBallMachineLearning-IJCGA , author={Frank Nielsen and Richard Nock} , title={Approximating smallest enclosing balls with applications to machine learning} , journal={International Journal on Computational Geometry and Applications} , month={October} , year={2009} , volume={19} , number={5} , pages={389-414 } , doi={10.1142/S0218195909003039} , abstract={ In this paper, we first survey prior work for computing exactly or approximately the smallest enclosing balls of point or ball sets in Euclidean spaces. We classify previous work into three categories: (1) purely combinatorial, (2) purely numerical, and (3) recent mixed hybrid algorithms based on coresets. We then describe two novel tailored algorithms for computing arbitrary close approximations of the smallest enclosing Euclidean ball of balls. These deterministic heuristics are based on solving relaxed decision problems using a primal-dual method. The primal-dual method is interpreted geometrically as solving for a minimum covering set, or dually as seeking for a minimum piercing set. Finally, we present some applications in machine learning of the exact and approximate smallest enclosing ball procedure, and discuss about its extension to non-Euclidean information- theoretic spaces. } }