Title
The dual and degrees of freedom of linearly constrained generalized lasso
Abstract
The lasso and its variants have attracted much attention recently because of its ability of simultaneous estimation and variable selection. When some prior knowledge exists in applications, the performance of estimation and variable selection can be further improved by incorporating the prior knowledge as constraints on parameters. In this article, we consider linearly constrained generalized lasso, where the constraints are either linear inequalities or equalities or both. The dual of the problem is derived, which is a much simpler problem than the original one. As a by-product, a coordinate descent algorithm is feasible to solve the dual. A formula for the number of degrees of freedom is derived. The method for selecting tuning parameter is also discussed.
Year
DOI
Venue
2015
10.1016/j.csda.2014.12.010
Computational Statistics & Data Analysis
Keywords
Field
DocType
constrained optimization,degrees of freedom,coordinate descent,kkt condition,lasso,duality
Mathematical optimization,Feature selection,Lasso (statistics),Duality (optimization),Coordinate descent,Karush–Kuhn–Tucker conditions,Linear inequality,Mathematics,Constrained optimization
Journal
Volume
Issue
ISSN
86
C
0167-9473
Citations 
PageRank 
References 
1
0.38
3
Authors
3
Name
Order
Citations
PageRank
Qinqin Hu110.38
Peng Zeng2255.33
Lu Lin3278.56