R: Extract Matrix or Square-Root Factor from Components of an...

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)

José Pinheiro and Douglas Bates bates@stat.wisc.edu

References

Pinheiro, J.C., and Bates, D.M. (2000) "Mixed-Effects Models in S and S-PLUS", Springer, esp. p. 162.

Examples

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

[Package nlme version 3.1-131 Index]