Paper ID | MLSP-28.6 | ||
Paper Title | On the Performance-Complexity Tradeoff in Stochastic Greedy Weak Submodular Optimization | ||
Authors | Abolfazl Hashemi, Haris Vikalo, Gustavo de Veciana, University of Texas at Austin, United States | ||
Session | MLSP-28: ML and Time Series | ||
Location | Gather.Town | ||
Session Time: | Thursday, 10 June, 14:00 - 14:45 | ||
Presentation Time: | Thursday, 10 June, 14:00 - 14:45 | ||
Presentation | Poster | ||
Topic | Machine Learning for Signal Processing: [OTH-BGDT] Big Data | ||
IEEE Xplore Open Preview | Click here to view in IEEE Xplore | ||
Abstract | Weak submodular optimization underpins many problems in signal processing and machine learning. For such problems, under a cardinality constraint, a simple greedy algorithm is guaranteed to find a solution with a value no worse than $1-e^{-\gamma}$ of the optimal. Given the high cost of queries to large-scale signal processing models, the complexity of \textsc{Greedy} becomes prohibitive in modern applications. In this work, we study the tradeoff between performance and complexity when one resorts to random sampling strategies to reduce the query complexity of \textsc{Greedy}. Specifically, we quantify the effect of uniform sampling strategies on the performance through two criteria: (i) the probability of identifying an optimal subset, and (ii) the suboptimality of the solution’s value with respect to the optimal. Building upon this insight, we propose a simple progressive stochastic greedy algorithm, study its approximation guarantees, and consider its applications to dimensionality reduction and feature selection tasks. |