Well, a variable with values 0/1 is useful for calculating observed probabilities by groups. But it is not diffcult to have the same variable both as numeric and as a factor in the dataframe and use each variation depending on the analysis. Angel
________________________________ De: Duncan Murdoch [mailto:murdoch.dun...@gmail.com] Enviado el: vie 19/09/2014 14:22 Para: Angel Rodriguez; r-help@r-project.org Asunto: Re: [R] See the numeric codes of a factor On 19/09/2014 8:12 AM, Angel Rodriguez wrote: > Re: [R] See the numeric codes of a factor > Thank you, Duncan. So isn't it possible to add labels to a variable > with numeric values 0/1? This kind of variable is very useful for > logistic regression, for example, but I'd rather have its > categories labelled. I think you are thinking of how you have done things in some other system. In R, a factor is fine in logistic regression, regardless of the fact that internally values are stored as 1 and 2. Duncan Murdoch > Angel > > ------------------------------------------------------------------------ > *De:* Duncan Murdoch [mailto:murdoch.dun...@gmail.com] > *Enviado el:* vie 19/09/2014 13:32 > *Para:* Angel Rodriguez; r-help@r-project.org > *Asunto:* Re: [R] See the numeric codes of a factor > > On 19/09/2014, 6:53 AM, Angel Rodriguez wrote: > > Dear Subscribers, > > > > I want to label a numeric variable 0="Bad" /1="Good". I understand > the only way is to transform it into a factor variable. > > > > Is there a way to check that the numeric values of the new factor > variable are 0 and 1 and not 1 and 2? > > If you apply as.numeric() to a factor, you won't get a zero value. > Internal factor values start at 1. > > So I wouldn't rely on the internal storage to achieve whatever it is you > want to achieve. Use explicit computation, e.g. > > words <- ifelse(var == 0, "Bad", ifelse(var == 1, "Good", NA)) > values <- ifelse(words == "Bad", 0, ifelse(words == "Good", 1, NA)) > > Duncan Murdoch > > > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.
