Abstract
Feature screening plays an important role in the analysis of ultrahigh dimensional data. Due to complicated model structure and high noise level, existing screening methods often suffer from model misspecification and the presence of outliers. To address these issues, we introduce a new metric named cumulative divergence (CD), and develop a CD-based forward screening procedure. This forward screening method is model-free and resistant to the presence of outliers in the response. It also incorporates the joint effects among covariates into the screening process. With a data-driven threshold, the new method can automatically determine the number of features that should be retained after screening. These merits make the CD-based screening very appealing in practice. Under certain regularity conditions, we show that the proposed method possesses sure screening property. The performance of our proposal is illustrated through simulations and a real data example. Supplementary materials for this article are available online.
Acknowledgments
The authors thank the AE, and the reviewers for their constructive comments, which have led to a significant improvement of the earlier version of this article. Liping Zhu is the corresponding author.
Supplementary Materials
The supplementary material contains the proofs of Statement (2.2), Lemma 2, Proposition 1 and Theorem 1.