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
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