Approximating data with a union of ellipsoids and clustering
I will introduce a surrogate for the distance function to the support of a distribution, which sublevel sets are unions of balls or of ellipsoids. I will expose different results, including rates of convergence for the approximadomtion of these surrogates with their empirical versions, built from pointclouds. I will explain how to use such estimators to cluster data with a geometric structure. The results have been published in the papers [1,2], and are still in progress. [1] C. Brécheteau. Robust anisotropic power-functions-based filtrations for clustering. In 36th International Symposium on Computational Geometry (SoCG 2020), vol. 164, 2020. [2] C. Brécheteau, C. Levrard. A k-points-based distance for robust geometric inference. Bernoulli, 26(4), 2020.