{ "id": "1710.07367", "version": "v1", "published": "2017-10-19T23:02:45.000Z", "updated": "2017-10-19T23:02:45.000Z", "title": "Convergence Analysis of the Frank-Wolfe Algorithm and Its Generalization in Banach Spaces", "authors": [ "Hong-Kun Xu" ], "comment": "27 pages", "categories": [ "math.OC" ], "abstract": "The Frank-Wolfe algorithm, a very first optimization method and also known as the conditional gradient method, was introduced by Frank and Wolfe in 1956. Due to its simple linear subproblems, the Frank-Wolfe algorithm has recently been received much attention for solving large-scale structured optimization problems arising from many applied areas such as signal processing and machine learning. In this paper we will discuss in detail the convergence analysis of the Frank-Wolfe algorithm in Banach spaces. Two ways of the selections of the stepsizes are discussed: the line minimization search method and the open loop rule. In both cases, we prove the convergence of the Frank-Wolfe algorithm in the case where the objective function $f$ has uniformly continuous (on bounded sets) Fr\\'echet derivative $f'$. We introduce the notion of the curvature constant of order $\\sigma\\in (1,2]$ and obtain the rate $O(\\frac{1}{k^{\\sigma-1}})$ of convergence of the Frank-Wolfe algorithm. In particular, this rate reduces to $O(\\frac{1}{k^{\\nu}})$ if $f'$ is $\\nu$-H\\\"older continuous for $\\nu\\in (0,1]$, and to $O(\\frac{1}{k})$ if $f'$ is Lipschitz continuous. A generalized Frank-Wolfe algorithm is also introduced to address the problem of minimizing a composite objective function. Convergence of iterates of both Frank-Wolfe and generalized Frank-Wolfe algorithms are investigated.", "revisions": [ { "version": "v1", "updated": "2017-10-19T23:02:45.000Z" } ], "analyses": { "subjects": [ "90C25", "65K05", "49M37" ], "keywords": [ "convergence analysis", "banach spaces", "generalized frank-wolfe algorithm", "structured optimization problems arising", "line minimization search method" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable" } } }