L0Learn: A Scalable Package for Sparse Learning using L0 Regularization

Authors: Hussein Hazimeh, Rahul Mazumder, Tim Nonet

JMLR 2023 | Venue PDF | Archive PDF | Plain Text | LLM Run Details

Reproducibility Variable Result LLM Response
Research Type Experimental Our main goal in these experiments is to compare the running time of L0Learn with similar toolkits, designed for sparse learning problems. Specifically, we compare with glmnet, ncvreg, picasso, and abess. For space constraints, we focus on linear regression, and refer the reader to Dedieu et al. (2021) for sparse classification experiments. Our experiments also shed some light on the statistical performance of the different approaches: for indepth studies of statistical properties, see Hazimeh and Mazumder (2020); Hastie et al. (2020); Mazumder et al. (2023).
Researcher Affiliation Collaboration Hussein Hazimeh EMAIL Google Research Rahul Mazumder EMAIL Massachusetts Institute of Technology Tim Nonet EMAIL Massachusetts Institute of Technology
Pseudocode No The paper describes algorithms in prose (e.g., "L0Learn uses a combination of (i) cyclic CD and (ii) local combinatorial optimization") but does not contain any clearly labeled pseudocode or algorithm blocks.
Open Source Code Yes We present L0Learn: an open-source package for sparse linear regression and classification using ℓ0 regularization. L0Learn is available on both CRAN and Git Hub.1 1Links: https://cran.r-project.org/package=L0Learn and https://github.com/hazimehh/L0Learn
Open Datasets No Following Hazimeh and Mazumder (2020), we consider synthetic data as per a linear regression model under the fixed design setting (exponential correlation model with ρ = 0.3).
Dataset Splits Yes cv_fit <L0Learn.cvfit(x, y, penalty="L0", n Folds =5) # 5-fold cross validation All competing methods are tuned to minimize MSE on a validation set with the same size as the training set.
Hardware Specification Yes Experiments were performed on a Linux c5n.2xlarge EC2 instance running R 4.0.2.
Software Dependencies Yes Experiments were performed on a Linux c5n.2xlarge EC2 instance running R 4.0.2.
Experiment Setup Yes In L0Learn, we used the default CD algorithm with the ℓ0ℓ2 penalty. In picasso, we used ℓ1 regularization and changed the convergence threshold (prec) to 10 10 so that its solutions roughly match those of glmnet. In ncvreg, we used the (default) MCP penalty. All competing methods are tuned to minimize MSE on a validation set with the same size as the training set. In L0Learn, ncvreg, and abess, we tune over a twodimensional grid consisting of 100 λ values (chosen automatically by the toolkits) and 100 γ values (in the range [10 2, 102] for L0Learn, [1.5, 103] for ncvreg, [1, 103] for abess4).