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arXiv · 1410.0247

A Practical Scheme and Fast Algorithm to Tune the Lasso With Optimality Guarantees

Michaël Chichignoud·Johannes Lederer·Martin Wainwright
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Abstract

We introduce a novel scheme for choosing the regularization parameter in high-dimensional linear regression with Lasso. This scheme, inspired by Lepski's method for bandwidth selection in non-parametric regression, is equipped with both optimal finite-sample guarantees and a fast algorithm. In particular, for any design matrix such that the Lasso has low sup-norm error under an "oracle choice" of the regularization parameter, we show that our method matches the oracle performance up to a small constant factor, and show that it can be implemented by performing simple tests along a single Lasso path. By applying the Lasso to simulated and real data, we find that our novel scheme can be faster and more accurate than standard schemes such as Cross-Validation.

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Michaël Chichignoud, Johannes Lederer, Martin Wainwright. 2014-10-01. A Practical Scheme and Fast Algorithm to Tune the Lasso With Optimality Guarantees. https://arxiv.org/abs/1410.0247

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