Renvlp (version 2.7)

testcoef.xenv: Hypothesis test of the coefficients of the envelope model

Description

This function tests the null hypothesis L * beta * R = A versus the alternative hypothesis L * beta * R ~= A, where beta is estimated under the envelope model in predictor space.

Usage

testcoef.xenv(m, L, R, A)

Arguments

m

A list containing estimators and other statistics inherited from xenv.

L

The matrix multiplied to beta on the left. It is a d1 by p matrix, while d1 is less than or equal to p.

R

The matrix multiplied to beta on the right. It is an r by d2 matrix, while d2 is less than or equal to r.

A

The matrix on the right hand side of the equation. It is a d1 by d2 matrix.

Value

The output is a list that contains following components.

chisqStatistic

The test statistic.

dof

The degrees of freedom of the reference chi-squared distribution.

pValue

p-value of the test.

covMatrix

The covariance matrix of vec(L beta R).

Details

This function tests for hypothesis H0: L beta R = A, versus Ha: L beta R != A. The beta is estimated by the envelope model in predictor space. If L = Ip, R = Ir and A = 0, then the test is equivalent to the standard F test on if beta = 0. The test statistic used is vec(L beta R - A) hatSigma^-1 vec(L beta R - A)^T, where beta is the envelope estimator and hatSigma is the estimated asymptotic covariance of vec(L beta R - A). The reference distribution is chi-squared distribution with degrees of freedom d1 * d2.

Examples

# NOT RUN {
data(wheatprotein)
X <- wheatprotein[, 1:6]
Y <- wheatprotein[, 7]
m <- xenv(X, Y, 2)
m

L <- diag(6)
R <- as.matrix(1)
A <- matrix(0, 6, 1)

test.res <- testcoef.xenv(m, L, R, A)
test.res
# }