Initialize reStruct Object

DESCRIPTION:

Initial estimates for the parameters in the pdMat objects forming object, which have not yet been initialized, are obtained using the methodology described in Bates and Pinheiro (1998). These estimates may be refined using a series of EM iterations, as described in Bates and Pinheiro (1998). The number of EM iterations to be used is defined in control.

USAGE:

initialize(object, data, conLin, control) 

REQUIRED ARGUMENTS:

object
an object inheriting from class reStruct, representing a random effects structure and consisting of a list of pdMat objects.
data
a data frame in which to evaluate the variables defined in formula(object).
conLin
a condensed linear model object, consisting of a list with components "Xy", corresponding to a regression matrix ( X) combined with a response vector ( y), and "logLik", corresponding to the log-likelihood of the underlying model.

OPTIONAL ARGUMENTS:

control
an optional list with a single component niterEM controlling the number of iterations for the EM algorithm used to refine initial parameter estimates. It is given as a list for compatibility with other initialize methods. Defaults to list(niterEM = 20).

VALUE:

an reStruct object similar to object, but with all pdMat components initialized.

REFERENCES:

Bates, D.M. and Pinheiro, J.C. (1998) "Computational methods for multilevel models" available in PostScript or PDF formats at http://nlme.stat.wisc.edu

SEE ALSO:

,