 
  
Covariance is of universal prevalence across various disciplines
within statistics. This package aims at providing a rich collection of
geometric and statistical tools for a variety of inferences on
covariance structures as well as its inverse called
precision matrix. See the package help file by
help("package-CovTools") in R console for the list of
available functions.
Installation
You can install the released version of CovTools from CRAN with:
install.packages("CovTools")
or the development version from github:
## install.packages("devtools")
## library(devtools)
devtools::install_github("kisungyou/CovTools")
List of Available Methods
We offer various methods for covariance and symmetric
positive-definite matrices. Below is the list of functions implemented
in our package.
(0) Elementary Operations
| CovDist | computes pairwise distance for symmetric
positive-definite matrices | 
| CovMean | estimate mean/average covariance
matrix | 
(1) Estimation : Covariance
| CovEst.adaptive | Cai and Liu (2011) | adaptive thresholding | 
| CovEst.hard | Bickel and Levina (2008) | hard thresholding | 
| CovEst.hardPD | Fan et al. (2013) | hard thresholding under
positive-definiteness constraint | 
| CovEst.nearPD | Qi and Sun (2006) | nearest positive-definite matrix
projection | 
| CovEst.soft | Antoniadis and Fan (2001) | soft thresholding | 
| CovEst.2003LW | Ledoit and Wolf (2003) | linear shrinkage estimation | 
| CovEst.2010OAS | Chen et al. (2010) | oracle approximation shrinkage | 
| CovEst.2010RBLW | Chen et al. (2010) | Rao-Blackwell Ledoit-Wolf estimation | 
(2) Estimation : Precision
| PreEst.2014An | An et al. (2014) | banded precision estimation via bandwidth
test | 
| PreEst.2014Banerjee | Banerjee and Ghosal (2014) | Bayesian estimation of a banded precision
matrix | 
| PreEst.2017Lee | Lee and Lee (2017) | Bayesian estimation of a banded precision
matrix | 
| PreEst.glasso | Friedman et al. (2008) | graphical lasso | 
(3) Hypothesis Test : 1-sample
| BCovTeset1.mxPBF | Lee et al. (2018) | Bayesian test using Maximum Pairwise Bayes
Factor | 
| CovTest1.2013Cai | Cai and Ma (2013) | Test by Cai and Ma | 
| CovTest1.2014Srivastava | Srivastava et al. (2014) | Test by Srivastava, Yanagihara, and
Kubokawa | 
(4) Hypothesis Test : 2-sample
| CovTest2.2013Cai | Cai and Ma (2013) | Test by Cai and Ma | 
(5) Hypothesis Test :
1-sample Diagonal
| BDiagTest1.mxPBF | Lee et al. (2018) | Bayesian Test using Maximum Pairwise Bayes
Factor | 
| DiagTest1.2011Cai | Cai and Jiang (2011) | Test by Cai and Jiang | 
| DiagTest1.2015Lan | Lan et al. (2015) | Test by Lan, Luo, Tsai, Wang, and
Yang |