Composable Coresets for Constrained Determinant Maximization and Beyond
作者: Sepideh Mahabadi, Thuy-Duong Vuong
摘要
We study algorithms for construction of composable coresets for the task of Determinant Maximization under partition constraint. Given a point set V ⊂ℝ^d that is partitioned into s groups V_1,⋯, V_s, and integers k_1,…,k_s, where k=∑_i k_i, the goal is to pick k_i points from group V_i such that the overall determinant of the picked k points is maximized. Determinant Maximization and its constrained variants have gained a lot of interest for modeling diversity, and have found applications in the context of data summarization. When the cardinality k of the selected set is greater than the dimension d, we show a peeling algorithm that gives us a composable coreset of size kd with a provably optimal approximation factor of d^O(d). When k≤ d, we show a simple coreset construction with optimal size and approximation factor. As a further application of our technique, we get a composable coreset for determinant maximization under the more general laminar matroid constraints, and a composable coreset for unconstrained determinant maximization in a previously unresolved regime. Our results generalize to all strongly Rayleigh distributions and to several other experimental design problems. As an application, we improve the runtime of the practical local-search based algorithm of [Anari-Vuong–COLT’22] for determinantal maximization under partition constraint from O(n^2^sk^2^s) to O(n k^2^s), making it only linear on the number of points n.