R: Modify terms objects

Modify terms objects

Usage

delete.response(termobj)
reformulate(termlabels,response=NULL)
drop.terms(termobj, dropx = NULL, keep.response = FALSE)

Arguments

`termobj`	A `terms` object
`termlabels`	vector of strings giving the right-hand side of a model formula
`response`	string giving the left-hand side of a model formula
`dropx`	vector of positions of variables to drop from the right-hand side of the model
`keep.response`	Keep the response in the resulting object?

Description

delete.response returns a terms object for the same model but with no response variable. drop.terms removes variables from the right-hand side of the model. reformulate creates a formula from a vector of strings.

Value

delete.response and drop.terms return a terms object; reformulate returns a formula.

Examples

ff<-y~z+x+w
tt<-terms(ff)
tt
delete.response(tt)
drop.terms(tt,2:3,keep.response=T)
reformulate(attr(tt,"term.labels"))