Extract Names from a formula

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.

# 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

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

See also

model.matrix, terms, Names

Examples

Names(distance ~ Sex * age, data = Orthodont)
#> [1] "(Intercept)"   "SexFemale"     "age"           "SexFemale:age"