Abstract | ||
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In this paper, we develop Stochastic Continuous Greedy++ (SCG++), the first efficient variant of a conditional gradient method for maximizing a continuous submodular function subject to a convex constraint. Concretely, for a monotone and continuous DR-submodular function, SCG++ achieves a tight [(1 − 1/e)OPT − ] solution while using O(1/ 2) stochastic gradients and O(1/) calls to the linear optimization oracle. The best previously known algorithms either achieve a suboptimal [(1/2)OPT − ] solution with O(1/ 2) stochastic gradients or the tight [(1 − 1/e)OPT − ] solution with suboptimal O(1/ 3) stochastic gradients. We further provide an information-theoretic lower bound to showcase the necessity of O(1/ 2) stochastic oracle queries in order to achieve [(1 − 1/e)OPT − ] for monotone and DR-submodular functions. This result shows that our proposed SCG++ enjoys optimality in terms of both approximation guarantee, i.e., (1−1/e) approximation factor, and stochastic gradient evaluations, i.e., O(1/ 2) calls to the stochastic oracle. By using stochastic continuous optimization as an interface, we also show that it is possible to obtain the [(1 − 1/e)OPT − ] tight approximation guarantee for maximizing a monotone but stochastic submodular set function subject to a general matroid constraint after at most O(n 2 / 2) calls to the stochastic function value, where n is the number of elements in the ground set. |
Year | Venue | Keywords |
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2019 | NeurIPS | continuous optimization,submodular function,conditional gradient method |
Field | DocType | Citations |
Mathematical optimization,Upper and lower bounds,Computer science | Conference | 0 |
PageRank | References | Authors |
0.34 | 0 | 4 |
Name | Order | Citations | PageRank |
---|---|---|---|
Amin Karbasi | 1 | 455 | 45.00 |
Seyed Hamed Hassani | 2 | 151 | 22.04 |
Aryan Mokhtari | 3 | 211 | 24.93 |
Zebang Shen | 4 | 17 | 9.36 |