{ "id": "2207.06503", "version": "v1", "published": "2022-07-13T19:51:24.000Z", "updated": "2022-07-13T19:51:24.000Z", "title": "Randomly pivoted Cholesky: Practical approximation of a kernel matrix with few entry evaluations", "authors": [ "Yifan Chen", "Ethan N. Epperly", "Joel A. Tropp", "Robert J. Webber" ], "comment": "28 pages, 4 figures", "categories": [ "math.NA", "cs.NA", "stat.ML" ], "abstract": "Randomly pivoted Cholesky (RPCholesky) is a natural algorithm for computing a rank-k approximation of an N x N positive semidefinite (psd) matrix. RPCholesky can be implemented with just a few lines of code. It requires only (k+1)N entry evaluations and O(k^2 N) additional arithmetic operations. This paper offers the first serious investigation of its experimental and theoretical behavior. Empirically, RPCholesky matches or improves on the performance of alternative algorithms for low-rank psd approximation. Furthermore, RPCholesky provably achieves near-optimal approximation guarantees. The simplicity, effectiveness, and robustness of this algorithm strongly support its use in scientific computing and machine learning applications.", "revisions": [ { "version": "v1", "updated": "2022-07-13T19:51:24.000Z" } ], "analyses": { "subjects": [ "65F55", "65C99", "68T05" ], "keywords": [ "randomly pivoted cholesky", "entry evaluations", "kernel matrix", "practical approximation", "provably achieves near-optimal approximation guarantees" ], "note": { "typesetting": "TeX", "pages": 28, "language": "en", "license": "arXiv", "status": "editable" } } }