Abstract | ||
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We consider a discrete optimization formulation for learning sparse classifiers, where the outcome depends upon a linear combination of a small subset of features. Recent work has shown that mixed integer programming (MIP) can be used to solve (to optimality) l(0)-regularized regression problems at scales much larger than what was conventionally considered possible. Despite their usefulness, MIP-based global optimization approaches are significantly slower than the relatively mature algorithms for l(1)-regularization and heuristics for nonconvex regularized problems. We aim to bridge this gap in computation times by developing new MIP-based algorithms for l(0)-regularized classification. We propose two classes of scalable algorithms: an exact algorithm that can handle p approximate to 50, 000 features in a few minutes, and approximate algorithms that can address instances with p approximate to 10(6) in times comparable to the fast l(1)-based algorithms. Our exact algorithm is based on the novel idea of integrality generation, which solves the original problem (with p binary variables) via a sequence of mixed integer programs that involve a small number of binary variables. Our approximate algorithms are based on coordinate descent and local combinatorial search. In addition, we present new estimation error bounds for a class of l(0)-regularized estimators. Experiments on real and synthetic data demonstrate that our approach leads to models with considerably improved statistical performance (especially variable selection) compared to competing methods. |
Year | DOI | Venue |
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2021 | v22/19-1049.html | JOURNAL OF MACHINE LEARNING RESEARCH |
Keywords | DocType | Volume |
sparsity, sparse classification, 10 regularization, mixed integer programming | Journal | 22 |
Issue | ISSN | Citations |
1 | 1532-4435 | 0 |
PageRank | References | Authors |
0.34 | 0 | 3 |
Name | Order | Citations | PageRank |
---|---|---|---|
Dedieu Antoine | 1 | 0 | 0.34 |
Hazimeh Hussein | 2 | 0 | 0.34 |
Rahul Mazumder | 3 | 308 | 18.33 |