Safe Feature Elimination for Non-Negativity Constrained Convex Optimization

Fuente: arXiv
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Autori principali: Folberth, James, Becker, Stephen
Natura: Preprint
Pubblicazione: 2019
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author Folberth, James
Becker, Stephen
author_facet Folberth, James
Becker, Stephen
contents Inspired by recent work on safe feature elimination for $1$-norm regularized least-squares, we develop strategies to eliminate features from convex optimization problems with non-negativity constraints. Our strategy is safe in the sense that it will only remove features/coordinates from the problem when they are guaranteed to be zero at a solution. To perform feature elimination we use an accurate, but not optimal, primal-dual feasible pair, making our methods robust and able to be used on ill-conditioned problems. We supplement our feature elimination problem with a method to construct an accurate dual feasible point from an accurate primal feasible point; this allows us to use a first-order method to find an accurate primal feasible point, then use that point to construct an accurate dual feasible point and perform feature elimination. Under reasonable conditions, our feature elimination strategy will eventually eliminate all zero features from the problem. As an application of our methods we show how safe feature elimination can be used to robustly certify the uniqueness of non-negative least-squares (NNLS) problems. We give numerical examples on a well-conditioned synthetic NNLS problem and a on set of 40000 extremely ill-conditioned NNLS problems arising in a microscopy application.
format Preprint
id arxiv_https___arxiv_org_abs_1907_10831
institution arXiv
publishDate 2019
record_format arxiv
spellingShingle Safe Feature Elimination for Non-Negativity Constrained Convex Optimization
Folberth, James
Becker, Stephen
Optimization and Control
Computer Vision and Pattern Recognition
49N15, 90C25, 90C46
Inspired by recent work on safe feature elimination for $1$-norm regularized least-squares, we develop strategies to eliminate features from convex optimization problems with non-negativity constraints. Our strategy is safe in the sense that it will only remove features/coordinates from the problem when they are guaranteed to be zero at a solution. To perform feature elimination we use an accurate, but not optimal, primal-dual feasible pair, making our methods robust and able to be used on ill-conditioned problems. We supplement our feature elimination problem with a method to construct an accurate dual feasible point from an accurate primal feasible point; this allows us to use a first-order method to find an accurate primal feasible point, then use that point to construct an accurate dual feasible point and perform feature elimination. Under reasonable conditions, our feature elimination strategy will eventually eliminate all zero features from the problem. As an application of our methods we show how safe feature elimination can be used to robustly certify the uniqueness of non-negative least-squares (NNLS) problems. We give numerical examples on a well-conditioned synthetic NNLS problem and a on set of 40000 extremely ill-conditioned NNLS problems arising in a microscopy application.
title Safe Feature Elimination for Non-Negativity Constrained Convex Optimization
topic Optimization and Control
Computer Vision and Pattern Recognition
49N15, 90C25, 90C46
url https://arxiv.org/abs/1907.10831