pdMatrix.reStruct {nlme}R Documentation

Extract Matrix or Square-Root Factor from Components of an reStruct Object

Description

This method function extracts the positive-definite matrices corresponding to the pdMat elements of object, or square-root factors of the positive-definite matrices.

Usage

## S3 method for class 'reStruct':
pdMatrix(object, factor)

Arguments

object an object inheriting from class reStruct, representing a random effects structure and consisting of a list of pdMat objects.
factor an optional logical value. If TRUE, square-root factors of the positive-definite matrices represented by the elements of object are returned; else, if FALSE, the positive-definite matrices are returned. Defaults to FALSE.

Value

a list with components given by the positive-definite matrices corresponding to the elements of object, or square-root factors of the positive-definite matrices.

Author(s)

Jose Pinheiro Jose.Pinheiro@pharma.novartis.com and Douglas Bates bates@stat.wisc.edu

See Also

as.matrix.reStruct, reStruct, pdMatrix.pdMat

Examples

data(Orthodont)
rs1 <- reStruct(pdSymm(diag(3), ~age+Sex, data = Orthodont))
pdMatrix(rs1)
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