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

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

[Package

*nlme* version 3.1-66

Index]