Skip to Main content Skip to Navigation
Preprints, Working Papers, ...

The degrees of freedom of the Group Lasso for a General Design

Abstract : In this paper, we are concerned with regression problems where covariates can be grouped in nonoverlapping blocks, and where only a few of them are assumed to be active. In such a situation, the group Lasso is an at- tractive method for variable selection since it promotes sparsity of the groups. We study the sensitivity of any group Lasso solution to the observations and provide its precise local parameterization. When the noise is Gaussian, this allows us to derive an unbiased estimator of the degrees of freedom of the group Lasso. This result holds true for any fixed design, no matter whether it is under- or overdetermined. With these results at hand, various model selec- tion criteria, such as the Stein Unbiased Risk Estimator (SURE), are readily available which can provide an objectively guided choice of the optimal group Lasso fit.
Document type :
Preprints, Working Papers, ...
Complete list of metadatas

Cited literature [24 references]  Display  Hide  Download
Contributor : Gabriel Peyré <>
Submitted on : Thursday, December 27, 2012 - 4:18:58 PM
Last modification on : Wednesday, September 23, 2020 - 4:30:31 AM
Long-term archiving on: : Thursday, March 28, 2013 - 3:48:31 AM


Files produced by the author(s)


  • HAL Id : hal-00768896, version 2
  • ARXIV : 1212.6478


Samuel Vaiter, Charles Deledalle, Gabriel Peyré, Jalal M. Fadili, Charles Dossal. The degrees of freedom of the Group Lasso for a General Design. 2012. ⟨hal-00768896v2⟩



Record views


Files downloads