Description Usage Arguments Details Value Author(s) References See Also Examples
View source: R/shrinkcovmat.unequal.R
Provides a nonparametric Stein-type shrinkage estimator of the covariance matrix that is a linear combination of the sample covariance matrix and of the diagonal matrix with elements the corresponding sample variances on the diagonal and zeros elsewhere.
1 | shrinkcovmat.unequal(data, centered = FALSE)
|
data |
a numeric matrix containing the data. |
centered |
a logical indicating if the vectors are centered around their mean vector. |
The rows of the data matrix data
correspond to variables and the
columns to subjects.
Returns an object of the class 'shrinkcovmathat' that has components:
Sigmahat |
The Stein-type shrinkage estimator of the covariance matrix. |
lambdahat |
The estimated optimal shrinkage intensity. |
Sigmasample |
The sample covariance matrix. |
Target |
The target covariance matrix. |
centered |
If the data are centered around their mean vector. |
Anestis Touloumis
Touloumis, A. (2015) nonparametric Stein-type Shrinkage Covariance Matrix Estimators in High-Dimensional Settings. Computational Statistics & Data Analysis 83, 251–261.
shrinkcovmat.equal
and
shrinkcovmat.identity
.
1 2 3 4 5 6 7 | data(colon)
normal_group <- colon[, 1:40]
tumor_group <- colon[, 41:62]
sigma_hat_normal_group <- shrinkcovmat.unequal(normal_group)
sigma_hat_normal_group
sigma_hat_tumor_group <- shrinkcovmat.unequal(tumor_group)
sigma_hat_tumor_group
|
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