Hi everybody! I'm sure that I overlook something and feel quite stupid to ask, but I have not found an easy solution to the following problem: Take e.g. the Orthodont data from the nlme package:> head(Orthodont)Grouped Data: distance ~ age | Subject distance age Subject Sex 1 26.0 8 M01 Male 2 25.0 10 M01 Male 3 29.0 12 M01 Male 4 31.0 14 M01 Male 5 21.5 8 M02 Male 6 22.5 10 M02 Male Suppose now, that I have a vector which contains the names of the "meta"-fields in this data-frame: metaFields <- c("Subject", "Sex") I now would like to form a new column "ID" which consists of the columns in metaFields joined like the following:> head(Orthodont)Grouped Data: distance ~ age | Subject distance age Subject Sex ID 1 26.0 8 M01 Male M01/Male 2 25.0 10 M01 Male M01/Male 3 29.0 12 M01 Male M01/Male 4 31.0 14 M01 Male M01/Male 5 21.5 8 M02 Male M02/Male 6 22.5 10 M02 Male M02/Male Any paste commands I tried so far ?failed, e.g.: Orthodont$ID <- paste(Orthodont[,metaFields], sep="/") is simply wrong. Ok, I could add the columns within a loop to ID, but that is not very elegant. Instead, what I need is a command that in effect produces the output of Orthodont$ID <- paste(Orthodont[,metaFields[1]], Orthodont[,metaFields[2]] , sep="/") There should be some way to do it in R - can someone please enlighten me? Thanks a lot in advance. Greetings, Sebastian
try this:
data("Orthodont", package = "nlme")
metaFields <- c("Subject", "Sex")
Orthodont$ID <- do.call("paste", c(Orthodont[metaFields], sep =
"/"))
I hope it helps.
Best,
Dimitris
----
Dimitris Rizopoulos
Biostatistical Centre
School of Public Health
Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
http://perswww.kuleuven.be/dimitris_rizopoulos/
----- Original Message -----
From: "Sebastian Weber" <sebastian.weber at
physik.tu-darmstadt.de>
To: <r-help at r-project.org>
Sent: Friday, July 18, 2008 9:36 AM
Subject: [R] column wise paste of data.frames
> Hi everybody!
>
> I'm sure that I overlook something and feel quite stupid to ask, but
> I
> have not found an easy solution to the following problem: Take e.g.
> the
> Orthodont data from the nlme package:
>
>> head(Orthodont)
> Grouped Data: distance ~ age | Subject
> distance age Subject Sex
> 1 26.0 8 M01 Male
> 2 25.0 10 M01 Male
> 3 29.0 12 M01 Male
> 4 31.0 14 M01 Male
> 5 21.5 8 M02 Male
> 6 22.5 10 M02 Male
>
> Suppose now, that I have a vector which contains the names of the
> "meta"-fields in this data-frame:
>
> metaFields <- c("Subject", "Sex")
>
> I now would like to form a new column "ID" which consists of the
> columns
> in metaFields joined like the following:
>
>> head(Orthodont)
> Grouped Data: distance ~ age | Subject
> distance age Subject Sex ID
> 1 26.0 8 M01 Male M01/Male
> 2 25.0 10 M01 Male M01/Male
> 3 29.0 12 M01 Male M01/Male
> 4 31.0 14 M01 Male M01/Male
> 5 21.5 8 M02 Male M02/Male
> 6 22.5 10 M02 Male M02/Male
>
> Any paste commands I tried so far ?failed, e.g.:
>
> Orthodont$ID <- paste(Orthodont[,metaFields], sep="/")
>
> is simply wrong. Ok, I could add the columns within a loop to ID,
> but
> that is not very elegant. Instead, what I need is a command that in
> effect produces the output of
>
> Orthodont$ID <- paste(Orthodont[,metaFields[1]],
> Orthodont[,metaFields[2]] , sep="/")
>
> There should be some way to do it in R - can someone please
> enlighten
> me? Thanks a lot in advance.
>
> Greetings,
>
> Sebastian
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm
do.call('paste', c(data.frame(letters, LETTERS),
list(sep='/')))
Patrick Burns
patrick at burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")
Sebastian Weber wrote:> Hi everybody!
>
> I'm sure that I overlook something and feel quite stupid to ask, but I
> have not found an easy solution to the following problem: Take e.g. the
> Orthodont data from the nlme package:
>
>
>> head(Orthodont)
>>
> Grouped Data: distance ~ age | Subject
> distance age Subject Sex
> 1 26.0 8 M01 Male
> 2 25.0 10 M01 Male
> 3 29.0 12 M01 Male
> 4 31.0 14 M01 Male
> 5 21.5 8 M02 Male
> 6 22.5 10 M02 Male
>
> Suppose now, that I have a vector which contains the names of the
> "meta"-fields in this data-frame:
>
> metaFields <- c("Subject", "Sex")
>
> I now would like to form a new column "ID" which consists of the
columns
> in metaFields joined like the following:
>
>
>> head(Orthodont)
>>
> Grouped Data: distance ~ age | Subject
> distance age Subject Sex ID
> 1 26.0 8 M01 Male M01/Male
> 2 25.0 10 M01 Male M01/Male
> 3 29.0 12 M01 Male M01/Male
> 4 31.0 14 M01 Male M01/Male
> 5 21.5 8 M02 Male M02/Male
> 6 22.5 10 M02 Male M02/Male
>
> Any paste commands I tried so far ?failed, e.g.:
>
> Orthodont$ID <- paste(Orthodont[,metaFields], sep="/")
>
> is simply wrong. Ok, I could add the columns within a loop to ID, but
> that is not very elegant. Instead, what I need is a command that in
> effect produces the output of
>
> Orthodont$ID <- paste(Orthodont[,metaFields[1]],
> Orthodont[,metaFields[2]] , sep="/")
>
> There should be some way to do it in R - can someone please enlighten
> me? Thanks a lot in advance.
>
> Greetings,
>
> Sebastian
>
> ______________________________________________
> 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.
>