R help - Feb 2009 - concatenating 2 text columns in a data.frame

Hi,

I'm trying to concatenate values from two columns in a data frame. For 
example, I have the following data.frame:

C1  C2  C3  C4  C5
 A   B   *F   C*   Q
 G   H   *I   J*   T
 K   D   *R   S*   E
 P   L   *M   N*   O

I'd like to concatenate text from columns C3 and C4, to yield either a 
list or vector, like so:

NewCol
  FC
  IJ
  RS
  MN

Is this feasible in R?

Thanks!

yes, try this:

dat <- read.table(textConnection(
"C1  C2  C3  C4  C5
A   B   F   C   Q
G   H   I   J   T
K   D   R   S   E
P   L   M   N   O"
), header = TRUE)
closeAllConnections()

dat$NewCol <- do.call(paste, c(dat[c("C3", "C4")], sep =
""))
dat


I hope it helps.

Best,
Dimitris


Shaun Grannis wrote:
> Hi,
> 
> I'm trying to concatenate values from two columns in a data frame. For 
> example, I have the following data.frame:
> 
> C1  C2  C3  C4  C5
> A   B   *F   C*   Q
> G   H   *I   J*   T
> K   D   *R   S*   E
> P   L   *M   N*   O
> 
> I'd like to concatenate text from columns C3 and C4, to yield either a 
> list or vector, like so:
> 
> NewCol
>  FC
>  IJ
>  RS
>  MN
> 
> Is this feasible in R?
> 
> Thanks!
> 
> ______________________________________________
> 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.
> 
-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014

On Mon, Feb 02, 2009 at 09:44:28AM -0500, Shaun Grannis
wrote:
> I'm trying to concatenate values from two columns in a data frame. For
> example, I have the following data.frame:
>
> C1  C2  C3  C4  C5
> A   B   *F   C*   Q
> G   H   *I   J*   T
> K   D   *R   S*   E
> P   L   *M   N*   O
>
> I'd like to concatenate text from columns C3 and C4, to yield either a
> list or vector, like so:
>
> NewCol
>  FC
>  IJ
>  RS
>  MN
assuming your data frame is named foo:

foo$NewCol <- paste(foo$C3, foo$C4, sep='')

cu
	Philipp

-- 
Dr. Philipp Pagel
Lehrstuhl f?r Genomorientierte Bioinformatik
Technische Universit?t M?nchen
Wissenschaftszentrum Weihenstephan
85350 Freising, Germany
http://mips.gsf.de/staff/pagel