Skip to main content
SLU publication database (SLUpub)

Research article2015Peer reviewed

Tests for high-dimensional covariance matrices using the theory of U-statistics

Ahmad, Rauf; Von Rosen, Dietrich; von Rosen, Dietrich

Abstract

Test statistics for sphericity and identity of the covariance matrix are presented, when the data are multivariate normal and the dimension, p, can exceed the sample size, n. Under certain mild conditions mainly on the traces of the unknown covariance matrix, and using the asymptotic theory of U-statistics, the test statistics are shown to follow an approximate normal distribution for large p, also when p >> n. The accuracy of the statistics is shown through simulation results, particularly emphasizing the case when p can be much larger than n. A real data set is used to illustrate the application of the proposed test statistics.

Keywords

covariance testing; U-statistics; high-dimensional data; sphericity

Published in

Journal of Statistical Computation and Simulation
2015, Volume: 85, number: 13, pages: 2619-2631
Publisher: TAYLOR & FRANCIS LTD