Re: [R] Concatenate a Variable

From: Marc Schwartz <marc_schwartz_at_comcast.net>
Date: Fri, 01 Feb 2008 08:36:59 -0600

Carla Rebelo wrote:
> Good morning!
>
> I do not speak English very well and so I will try to explain the best I
> can. I have this:
>
> > tabela[,1]
> [1] a a b b a c b a c c c c c
> Levels: a b c
>
> >unique(tabela[,1])
> [1] a b c
> Levels: a b c
>
> >var<-unique(tabela[,1])[1]
>
> > var
> [1] a
> Levels: a b c
>
> But if I concatenate like this
> > cat("VAR: ", var, "\n")
>
> I obtain
> >VAR: 1
>
> and I want to obtain
> >VAR: a
>
> How can I do this? Thanks!

'a' is a factor, thus you are getting the underlying numeric code as the output.

Note from ?cat:

Currently only atomic vectors (and so not lists) and names are handled. Character strings are output ‘as is’ (unlike print.default which escapes non-printable characters and backslash — use encodeString if you want to output encoded strings using cat). Other types of R object should be converted (e.g. by as.character or format) before being passed to cat.

Thus:

var <- factor("a", levels = c("a", "b", "c"))

> var

[1] a
Levels: a b c

> is.vector(var)

[1] FALSE So 'var' is not an atomic vector and you must therefore coerce it to a character vector using as.character() before passing it to cat():

> cat("VAR: ", as.character(var), "\n")
VAR: a

HTH, Marc Schwartz



R-help_at_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. Received on Fri 01 Feb 2008 - 14:39:59 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Fri 01 Feb 2008 - 15:30:11 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive