lmerMatrices {VCA}

Derive and Compute Matrices for Objects Fitted by Function 'lmer'

Description

Function derives and computes all matrices required for down-stream analyses of VCA-objects fitted with REML via function lmer.

Usage

lmerMatrices(obj, tab = NULL, terms = NULL, cov = FALSE, X = NULL)

Arguments

obj

(object) inheriting from 'lmerMod'

tab

(data.frame) representing the basic VCA-table

terms

(character) vector used for ordering variance components

cov

(logical) take non-zero covariances among random effects into account (TRUE) or not (FALSE), the latter is the default in this package and also implemented in remlVCA, anovaVCA, and anovaMM.

X

(matrix) design matrix of fixed effects as constructed to meet VCA-package requirements

Details

Mixed Model Equations (MME) are solved for fixed and random effects applying the same constraints as in anovaMM. The most elaborate and therefore time consuming part is to prepare all matrices required for approximating the variance-covariance matrix of variance components (see getGB). To reduce the computational time, this function tries to optimize object-classes depending on whether Intel's (M)ath (K)ernel (L)ibrary could be loaded or not. MKL appears to be more performant with ordinary matrix-objects, whereas all other computations are perfomred using matrix-representations of the Matrix-package.

This function is not intended to be called directly by users and therefore not exported.

Value

(list), a premature 'VCA' object

Author(s)

Andre Schuetzenmeister [e-mail]

See Also

remlVCA, remlMM