testcoef.genv {Renvlp} | R Documentation |
Hypothesis test of the coefficients of the groupwise 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 groupwise envelope model.
Usage
testcoef.genv(m, L, R, A)
Arguments
m |
A list containing estimators and other statistics inherited from genv. |
L |
The matrix multiplied to beta on the left. It is a d1 by r matrix, while d1 is less than or equal to r. |
R |
The matrix multiplied to beta on the right. It is a p by d2 matrix, while d2 is less than or equal to p. |
A |
The matrix on the right hand side of the equation. It is a d1 by d2 matrix. |
Note that inputs L
, R
and A
must be matrices, if not, use as.matrix
to convert them.
Details
This function tests for hypothesis H0: L beta[[i]] R = A, versus Ha: L beta[[i]] R != A. The beta is estimated by the groupwise envelope model. If L = Ir, R = Ip and A = 0, then the test is equivalent to the standard F test on if beta[[i]] = 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.
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). |
Examples
data(fiberpaper)
X <- fiberpaper[ , c(5, 7)]
Y <- fiberpaper[ , 1:3]
Z <- as.numeric(fiberpaper[ , 6] > mean(fiberpaper[ , 6]))
u <- u.genv(X, Y, Z)
u
m <- genv(X, Y, Z, 2)
m
L <- diag(3)
R <- diag(2)
A <- matrix(0, 3, 2)
test.res <- testcoef.genv(m, L, R, A)
test.res