Stable Estimation of a Covariance Matrix Guided by Nuclear Norm Penalties

Eric C. Chi,K. Lange

Published 2013 in Computational Statistics & Data Analysis

ABSTRACT

Estimation of a covariance matrix or its inverse plays a central role in many statistical methods. For these methods to work reliably, estimated matrices must not only be invertible but also well-conditioned. The current paper introduces a novel prior to ensure a well-conditioned maximum a posteriori (MAP) covariance estimate. The prior shrinks the sample covariance estimator towards a stable target and leads to a MAP estimator that is consistent and asymptotically efficient. Thus, the MAP estimator gracefully transitions towards the sample covariance matrix as the number of samples grows relative to the number of covariates. The utility of the MAP estimator is demonstrated in two standard applications - discriminant analysis and EM clustering - in this sampling regime.

PUBLICATION RECORD

CITATION MAP

EXTRACTION MAP

CLAIMS

  • No claims are published for this paper.

CONCEPTS

  • No concepts are published for this paper.

REFERENCES

Showing 1-52 of 52 references · Page 1 of 1

CITED BY

Showing 1-37 of 37 citing papers · Page 1 of 1