{ "id": "1812.08485", "version": "v1", "published": "2018-12-20T11:13:24.000Z", "updated": "2018-12-20T11:13:24.000Z", "title": "First-order algorithms converge faster than $O(1/k)$ on convex problems", "authors": [ "Ching-pei Lee", "Stephen J. Wright" ], "categories": [ "math.OC" ], "abstract": "It has been known for many years that both gradient descent and stochastic coordinate descent achieve a global convergence rate of $O(1/k)$ in the objective value, when applied to a scheme for minimizing a Lipschitz-continuously differentiable, unconstrained convex function. In this work, we improve this rate to $o(1/k)$. We extend the result to proximal gradient and proximal coordinate descent on regularized problems to show similar $o(1/k)$ convergence rates. The result is tight in the sense that an $O(1/k^{1+\\epsilon})$ rate is not generally attainable for any $\\epsilon>0$, for any of these methods.", "revisions": [ { "version": "v1", "updated": "2018-12-20T11:13:24.000Z" } ], "analyses": { "keywords": [ "first-order algorithms converge faster", "convex problems", "stochastic coordinate descent achieve", "proximal coordinate descent", "global convergence rate" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }