as_lmerModLmerTest function

Coerce lmerMod Objects to lmerModLmerTest

Coercing an lme4::lmer model-object (of class 'lmerMod') to a model-object of class 'lmerModLmerTest' involves computing the covariance matrix of the variance parameters and the gradient (Jacobian) of cov(beta) with respect to the variance parameters.

as_lmerModLmerTest(model, tol = 1e-08)

Arguments

• model: and lmer model-object (of class 'lmerMod') -- the result of a call to lme4::lmer()
• tol: tolerance for determining of eigenvalues are negative, zero or positive

Returns

an object of class 'lmerModLmerTest' which sets the following slots: - vcov_varpar: the asymptotic covariance matrix of the variance parameters (theta, sigma).

• Jac_list: list of Jacobian matrices; gradients of vcov(beta) with respect to the variance parameters.

• vcov_beta: the asymptotic covariance matrix of the fixed-effect regression parameters (beta; vcov(beta)).

• sigma: the residual standard deviation.

Examples

m <- lme4::lmer(Reaction ~ Days + (Days | Subject), sleepstudy)
bm <- as_lmerModLmerTest(m)
slotNames(bm)

See Also

the class definition in lmerModLmerTest) and lmer

Author(s)

Rune Haubo B. Christensen