[R] Join data frame columns

[Bert Gunter]

I don't think so. The OP wanted the list by columns, not rows, if I
understand correctly.

unlist(df)

provides this. Of course, the request probably does not makes sense in
the first place, as the different types/classes in the data.frame will
be coerced to one type/class. Moreover, factors will become numeric
(is this what motivated the original request??):

> dat <- data.frame(a = 1:3, b=letters[1:3])
> dat
  a b
1 1 a
2 2 b
3 3 c
> unlist(dat)
a1 a2 a3 b1 b2 b3
 1  2  3  1  2  3

So, a guess would be that the OP wants:

> unlist(lapply(dat,as.character))
 a1  a2  a3  b1  b2  b3
"1" "2" "3" "a" "b" "c"

But without the requested reproducible example, this is only a guess.
Again, note the coercion of numerics to character.

I would also guess that the OP might benefit by reading the Intro to R
tutorial and the data frame section of the R Language Definition
Manual -- and perhaps ?data.frame -- to better understand the nature
of data frames and what can and cannot be done with them.

Of course, I may have missed the mark altogether, in which case, please ignore.

-- Bert

On Tue, Oct 23, 2012 at 6:48 AM, Rui Barradas <ruipbarradas at sapo.pt> wrote:
> Hello,
>
> Use apply/paste.
>
> apply(df, 1, paste, collapse = "")  # outputs a vector
>
> Also, df is the name of an R function, you should choose something else, it
> can become confusing.
>
> Hope this helps,
>
> Rui Barradas
> Em 23-10-2012 12:45, brunosm escreveu:
>>
>> Hi,
>>
>> I have a data frame with 100 variables (numeric and non numeric types),
>> and
>> I want to join them in only one column, like a vector, but i want to keep
>> the non numeric variables like they are.
>>
>> I know that i can do something like this:
>>
>> Suppose that my data is in df variable
>>
>> new_df<-data.frame(c(df[,1],df[,2],df[,3],df[,4],...........)
>>
>> This works but i have 100 variables!
>>
>> Any way of doing this a little bit faster?
>>
>> Thanks a lot!
>>
>>
>>
>>
>>
>> --
>> View this message in context:
>> http://r.789695.n4.nabble.com/Join-data-frame-columns-tp4647113.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
>> 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.
>
>
> ______________________________________________
> 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.



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

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