R: Extract Names from a formula

Names.formula {nlme} | R Documentation

## Extract Names from a formula

### Description

This method function returns the names of the terms corresponding to the right hand side of `object` (treated as a linear formula), obtained as the column names of the corresponding `model.matrix`.

### Usage

    ## S3 method for class 'formula':
    Names(object, data, exclude, ...)

### Arguments

`object` | an object inheriting from class `formula`.
`data` | an optional data frame containing the variables specified in `object`. By default the variables are taken from the environment from which `Names.formula` is called.
`exclude` | an optional character vector with names to be excluded from the returned value. Default is `c("pi",".")`.
`...` | some methods for this generic require additional arguments. None are used in this method.

### Value

a character vector with the column names of the `model.matrix` corresponding to the right hand side of `object` which are not listed in `excluded`.

### Author(s)

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

### See Also

`model.matrix`, `terms`, `Names`

### Examples

    Names(distance ~ Sex * age, data = Orthodont)

[Package nlme version 3.1-89 Index]