lm_ShVAR_KCV: K-fold Cross Validation for Selection of Shrinkage Parameters...

Description Usage Arguments Details References

View source: R/lm_ShVAR_KCV.R

Description

Estimate regression coefficients and scale matrix for noise by using semiparametric Bayesian shrinkage estimator, whose shrinkage parameters are selected by K-fold cross validation (KCV).

Usage

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lm_ShVAR_KCV(Y, X, dof = Inf, lambda = NULL, lambda_var = NULL,
  prior_type = c("NCJ", "CJ"), num_folds = 5, m0 = ncol(Y))

Arguments

Y

An N x K matrix of dependent variables.

X

An N x M matrix of regressors.

dof

Degree of freedom for multivariate t-distribution. If dof = Inf (default), then multivariate normal distribution is applied and weight vector q is not estimated. If dof = NULL or a numeric vector, then dof is selected by K-fold CV automatically and q is estimated.

lambda

If NULL or a vector of length >=2, it is selected by KCV.

lambda_var

If NULL or a vector of length >=2, it is selected by KCV.

prior_type

"NCJ" for non-conjugate prior and "CJ" for conjugate prior for scale matrix Sigma.

num_folds

Number of folds for KCV.

m0

A hyperparameter for inverse Wishart distribution for Sigma

Details

The shrinkage parameters, lambda and lambda_var, for the semiparametric Bayesian shrinkage estimator are selected by KCV. See help(lm_semi_Bayes_PCV) for details about semiparametric Bayesian estimator.

References

N. Lee, H. Choi, and S.-H. Kim (2016). Bayes shrinkage estimation for high-dimensional VAR models with scale mixture of normal distributions for noise. Computational Statistics & Data Analysis 101, 250-276. doi: 10.1016/j.csda.2016.03.007


VARshrink documentation built on Oct. 9, 2019, 5:06 p.m.