Title
Rate Minimaxity of the Lasso and Dantzig Selector for the lq Loss in lr Balls
Abstract
We consider the estimation of regression coefficients in a high-dimensional linear model. For regression coefficients in lr balls, we provide lower bounds for the minimax lq risk and minimax quantiles of the lq loss for all design matrices. Under an l0 sparsity condition on a target coefficient vector, we sharpen and unify existing oracle inequalities for the Lasso and Dantzig selector. We derive oracle inequalities for target coefficient vectors with many small elements and smaller threshold levels than the universal threshold. These oracle inequalities provide sufficient conditions on the design matrix for the rate minimaxity of the Lasso and Dantzig selector for the lq risk and loss in lr balls, 0≤ r≤ 1≤ q≤ ∞. By allowing q=∞, our risk bounds imply the variable selection consistency of threshold Lasso and Dantzig selectors.
Year
DOI
Venue
2010
10.5555/1756006.1953043
Journal of Machine Learning Research
Keywords
DocType
Volume
lq risk,target coefficient vector,lr ball,lq loss,design matrix,risk bound,minimax lq risk,lr Balls,Dantzig Selector,lq Loss,Rate Minimaxity,oracle inequality,regression coefficient,Dantzig selector
Journal
11,
ISSN
Citations 
PageRank 
1532-4435
3
0.66
References 
Authors
4
2
Name
Order
Citations
PageRank
Fei Ye1244.54
Cun-Hui Zhang217418.38