formula.pdBlocked {nlme} | R Documentation |

## Extract pdBlocked Formula

### Description

The `formula`

attributes of the `pdMat`

elements of
`x`

are extracted and returned as a list, in case
`asList=TRUE`

, or converted to a single one-sided formula when
`asList=FALSE`

. If the `pdMat`

elements do not have a
`formula`

attribute, a `NULL`

value is returned.

### Usage

## S3 method for class 'pdBlocked':
formula(x, asList, ...)

### Arguments

`x` |
an object inheriting from class `pdBlocked` ,
representing a positive definite block diagonal matrix. |

`asList` |
an optional logical value. If `TRUE` , a list with
the formulas for the individual block diagonal elements of
`x` is returned; else, if `FALSE` , a one-sided formula
combining all individual formulas is returned. Defaults to
`FALSE` . |

`...` |
some methods for this generic require additional
arguments. None are used in this method. |

### Value

a list of one-sided formulas, or a single one-sided formula, or
`NULL`

.

### Author(s)

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

### See Also

`pdBlocked`

, `pdMat`

### Examples

pd1 <- pdBlocked(list(~ age, ~ Sex - 1))
formula(pd1)
formula(pd1, asList = TRUE)

[Package

*nlme* version 3.1-57

Index]