Thank you very much. This is exactly what I needed. Isaac.
-----Mensaje original----- De: peter dalgaard [mailto:pda...@gmail.com] Enviado el: lunes, 10 de diciembre de 2018 15:10 Para: Subirana Cachinero, Isaac CC: Rui Barradas; r-help@r-project.org Asunto: Re: [R] repeating the same variable in formula You might be looking for this: > all.vars(~chol+age+age, unique=FALSE) [1] "chol" "age" "age" -pd > On 10 Dec 2018, at 11:35 , Subirana Cachinero, Isaac <isubir...@imim.es> > wrote: > > Thank you for your response. > In fact, I use the formula environament to select variables, as part of the > code of another function. > I would like to allow the user to select the same variable more than once. > The use of I() may partly solve the problem. However, I would like > attr(terms(g),"term.labels") would return a vector with as many components as > variables including repetitions. And using I() function, there would be some > work remaining to split "I(age + age)" into "age", "age", taking into account > that in other examples variable may include white spaces or other characters > within ` `. > > Isaac. > > -----Mensaje original----- > De: Rui Barradas [mailto:ruipbarra...@sapo.pt] > Enviado el: lunes, 10 de diciembre de 2018 11:27 > Para: Subirana Cachinero, Isaac; r-help@r-project.org > Asunto: Re: [R] repeating the same variable in formula > > Hello, > > The formulas > > y ~ cholesterol + age + age > > and > > y ~ cholesterol + age > > are the same formula. > If you want 'age' twice, maybe > > g <- y ~ cholesterol + I(age + age) > attr(terms(g), "term.labels") > #[1] "cholesterol" "I(age + age)" > > > Hope this helps, > > Rui Barradas > > Às 06:49 de 10/12/2018, Subirana Cachinero, Isaac escreveu: >> y ~ cholesterol + age + age > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
