Extract Square-Root Factor from Components of an reStruct Object
Usage
pdFactor(object)
Arguments
object
|
an object inheriting from class reStruct ,
representing a random effects structure and consisting of a list of
pdMat objects.
|
Description
This method function extracts square-root factors of the
positive-definite matrices corresponding to the pdMat
elements
of object
.Value
a vector with square-root factors of the positive-definite matrices
corresponding to the elements of object
stacked column-wise.Note
This function is used intensively in optimization
algorithms and its value is returned as a vector for efficiency
reasons. The pdMatrix
function can be used to obtain
square-root factors in matrix form.Author(s)
Jose Pinheiro and Douglas BatesSee Also
pdMatrix.reStruct
, pdFactor.pdMat
Examples
library(lme)
data(Orthodont)
rs1 <- reStruct(pdSymm(diag(3), ~age+Sex, data = Orthodont))
pdFactor(rs1)