Names.formula              package: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)

