R help - Mar 2007 - for loop in assigning column names

R-help,

I have a data frame (df) and I want to add some columns whose names
should correspond to the "i" index in the loop below.

 for(i in 1:10)
 {
df$eval(paste("St", as.character(i), sep = "" ))  <-
ObJeCt[i]
 }

An error message comes out : 

"Error: attempt to apply non-function"

How can I get around this?

I could do something like :

df$St2 <- NA
df$St3 <- NA
dft$St4 < -NA
..

and afterwards assign the results of the loop above 
to the columns df$St2,df$St3,,,,,,,,,,,

The problem is that my object "ObJeCt[i]" may change in size
and definition and therefore a way to systematize the task would
be desirable.

Thanks in advance
> version
               _                           
platform       i386-pc-mingw32             
arch           i386                        
os             mingw32                     
system         i386, mingw32               
status                                     
major          2                           
minor          4.1                         
year           2006                        
month          12                          
day            18                          
svn rev        40228                       
language       R                           
version.string R version 2.4.1 (2006-12-18)

Have you tried something like

df <- cbind(df, ObJeCT[, 1:10])

Cheers,

Thierry

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Reseach Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx op inbo.be
www.inbo.be 

Do not put your faith in what statistics say until you have carefully
considered what they do not say.  ~William W. Watt
A statistical analysis, properly conducted, is a delicate dissection of
uncertainties, a surgery of suppositions. ~M.J.Moroney

 
> -----Oorspronkelijk bericht-----
> Van: r-help-bounces op stat.math.ethz.ch 
> [mailto:r-help-bounces op stat.math.ethz.ch] Namens Luis Ridao Cruz
> Verzonden: woensdag 21 maart 2007 16:14
> Aan: r-help op stat.math.ethz.ch
> Onderwerp: [R] for loop in assigning column names
> 
> R-help,
> 
> I have a data frame (df) and I want to add some columns whose 
> names should correspond to the "i" index in the loop below.
> 
>  for(i in 1:10)
>  {
> df$eval(paste("St", as.character(i), sep = "" ))  <-
ObJeCt[i]  }
> 
> An error message comes out : 
> 
> "Error: attempt to apply non-function"
> 
> How can I get around this?
> 
> I could do something like :
> 
> df$St2 <- NA
> df$St3 <- NA
> dft$St4 < -NA
> ..
> 
> and afterwards assign the results of the loop above to the 
> columns df$St2,df$St3,,,,,,,,,,,
> 
> The problem is that my object "ObJeCt[i]" may change in size 
> and definition and therefore a way to systematize the task 
> would be desirable.
> 
> Thanks in advance
> 
> > version
>                _                           
> platform       i386-pc-mingw32             
> arch           i386                        
> os             mingw32                     
> system         i386, mingw32               
> status                                     
> major          2                           
> minor          4.1                         
> year           2006                        
> month          12                          
> day            18                          
> svn rev        40228                       
> language       R                           
> version.string R version 2.4.1 (2006-12-18)
> 
> ______________________________________________
> R-help op stat.math.ethz.ch 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.
>

try

df.new <- cbind(df, ObJeCt[1:10])
names(df.new) <- c(names(df), paste("St", 1:10, sep =
""))


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
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://www.student.kuleuven.be/~m0390867/dimitris.htm



----- Original Message ----- 
From: "Luis Ridao Cruz" <Luisr at frs.fo>
To: <r-help at stat.math.ethz.ch>
Sent: Wednesday, March 21, 2007 4:14 PM
Subject: [R] for loop in assigning column names

> R-help,
>
> I have a data frame (df) and I want to add some columns whose names
> should correspond to the "i" index in the loop below.
>
> for(i in 1:10)
> {
> df$eval(paste("St", as.character(i), sep = "" ))  <-
ObJeCt[i]
> }
>
> An error message comes out :
>
> "Error: attempt to apply non-function"
>
> How can I get around this?
>
> I could do something like :
>
> df$St2 <- NA
> df$St3 <- NA
> dft$St4 < -NA
> ..
>
> and afterwards assign the results of the loop above
> to the columns df$St2,df$St3,,,,,,,,,,,
>
> The problem is that my object "ObJeCt[i]" may change in size
> and definition and therefore a way to systematize the task would
> be desirable.
>
> Thanks in advance
>
>> version
>               _
> platform       i386-pc-mingw32
> arch           i386
> os             mingw32
> system         i386, mingw32
> status
> major          2
> minor          4.1
> year           2006
> month          12
> day            18
> svn rev        40228
> language       R
> version.string R version 2.4.1 (2006-12-18)
>
> ______________________________________________
> R-help at stat.math.ethz.ch 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