A convex framework for high-dimensional sparse Cholesky based covariance estimation

K Khare, S Oh, S Rahman, B Rajaratnam - arXiv preprint arXiv …, 2016 - arxiv.org
Covariance estimation for high-dimensional datasets is a fundamental problem in modern
day statistics with numerous applications. In these high dimensional datasets, the number of …

A scalable sparse Cholesky based approach for learning high-dimensional covariance matrices in ordered data

K Khare, SY Oh, S Rahman, B Rajaratnam - Machine Learning, 2019 - Springer
Covariance estimation for high-dimensional datasets is a fundamental problem in machine
learning, and has numerous applications. In these high-dimensional settings the number of …

High dimensional sparse covariance estimation via directed acyclic graphs

P Rütimann, P Bühlmann - 2009 - projecteuclid.org
We present a graph-based technique for estimating sparse covariance matrices and their
inverses from high-dimensional data. The method is based on learning a directed acyclic …

A unified approach to penalized likelihood estimation of covariance matrices in high dimensions

L Cibinel, A Roverato, V Vinciotti - arXiv preprint arXiv:2410.02403, 2024 - arxiv.org
We consider the problem of estimation of a covariance matrix for Gaussian data in a high
dimensional setting. Existing approaches include maximum likelihood estimation under a …

On variable ordination of Cholesky‐based estimation for a sparse covariance matrix

X Kang, X Deng - Canadian Journal of Statistics, 2021 - Wiley Online Library
Estimation of a large sparse covariance matrix is of great importance for statistical analysis,
especially in high‐dimensional settings. The traditional approach such as the sample …

Towards a sparse, scalable, and stably positive definite (inverse) covariance estimator

SY Oh, B Rajaratnam, JH Won - arXiv preprint arXiv:1502.00471, 2015 - arxiv.org
High dimensional covariance estimation and graphical models is a contemporary topic in
statistics and machine learning having widespread applications. An important line of …

[HTML][HTML] The Bayesian covariance lasso

ZS Khondker, H Zhu, H Chu, W Lin… - Statistics and its …, 2013 - ncbi.nlm.nih.gov
Estimation of sparse covariance matrices and their inverse subject to positive definiteness
constraints has drawn a lot of attention in recent years. The abundance of high-dimensional …

[PDF][PDF] QUIC: quadratic approximation for sparse inverse covariance estimation.

CJ Hsieh, MA Sustik, IS Dhillon, P Ravikumar - J. Mach. Learn. Res., 2014 - jmlr.org
The l1-regularized Gaussian maximum likelihood estimator (MLE) has been shown to have
strong statistical guarantees in recovering a sparse inverse covariance matrix, or …

Covariance estimation: The GLM and regularization perspectives

M Pourahmadi - 2011 - projecteuclid.org
Finding an unconstrained and statistically interpretable reparameterization of a covariance
matrix is still an open problem in statistics. Its solution is of central importance in covariance …

Sparse estimation of large covariance matrices via a nested lasso penalty

E Levina, A Rothman, J Zhu - 2008 - projecteuclid.org
The paper proposes a new covariance estimator for large covariance matrices when the
variables have a natural ordering. Using the Cholesky decomposition of the inverse, we …