[R] colnames of a column

[Peter Alspach]

Alfredo 

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Alfredo 
> Alessandrini
> Sent: Friday, 20 June 2008 10:56 a.m.
> To: r-help at r-project.org
> Subject: [R] colnames of a column
> 
> Hi,
> 
> With this data.frame:
> 
> > class(rwl)
> [1] "data.frame"
> 
> >rwl
>   0028002F 0028013F 0028032F
> 1833     3.39       NA       NA
> 1834     3.09       NA       NA
> 1835     3.05       NA       NA
> 1836     3.31       NA       NA
> 1837     2.26       NA       NA
> 
> > colnames(rwl)
> [1] "0028002F" "0028013F" "0028032F"
> 
> Ok....
> 
> > colnames(rwl[,1])
> NULL
> 
> why?? I expect: "0028002F"

Because rwl[,1] is a numeric vector and not a dataframe:

is.data.frame(rwl[,1])
[1] FALSE

You probably want

names(rwl)[1]

HTH ....

Peter Alspach

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