[R] passing dataframe col name through cbind()

[jim holtman]

Try this:

> cbind(scores[,1,drop = FALSE], scores[,2:3])
  name round1 round2
1  Bob     40      5
2  Ron     30      6
3  Bud     20      4
>

Then do ?'[' to learn about 'drop'

On Tue, Nov 8, 2011 at 1:06 PM, Eric Rupley <erupley at umich.edu> wrote:
>
>
>
> Hi all ---
>
> I note that the column name of the first column in a dataframe does not necessarily get passed on when using cbind (example below)…
>
> I'm looking for help in clarifying why this behavior occurs, and how I can get all col names, including the first, passed on to the result…while I suspect it's obvious and documented to the cognoscenti, it's puzzling me…
>
> Many thanks for any help on this...
> Eric
>
>> scores <- data.frame(name=c("Bob","Ron","Bud"),round1=c(40,30,20),round2=c(5,6,4)) #some toy data
>>
>> scores
>  name round1 round2
> 1  Bob     40      5
> 2  Ron     30      6
> 3  Bud     20      4
>>
>
>> cbind(scores[,1],total=rowSums(scores[,2:3]),scores[,2:3])
>  scores[, 1] total round1 round2
> 1         Bob    45     40      5
> 2         Ron    36     30      6
> 3         Bud    24     20      4
>>
>
> ...first column renamed...
>
> …yet this passes all column names:
>
>> cbind(scores[,1:3])
>  name round1 round2
> 1  Bob     40      5
> 2  Ron     30      6
> 3  Bud     20      4
>>
>
> …but this doesn't:
>
>> cbind(scores[,1],scores[,2:3])
>  scores[, 1] round1 round2
> 1         Bob     40      5
> 2         Ron     30      6
> 3         Bud     20      4
>
>
> --
>  Eric Rupley
>  University of Michigan, Museum of Anthropology
>  1109 Geddes Ave, Rm. 4013
>  Ann Arbor, MI 48109-1079
>
>  erupley at umich.edu
>  +1.734.276.8572
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> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.