[R] How to order some of my columns (not rows) alphabetically

David Scott d.scott at auckland.ac.nz
Fri Sep 26 01:00:52 CEST 2008


On Thu, 25 Sep 2008, Mark Na wrote:

> Hello,
>
> I have a dataframe with 9 columns, and I would like to sort (order) the 
> right-most eight of them alphabetiaclly, i.e.:
>
> ID1 ID2 F G A B C E D
>
> would become
>
> ID1 ID2 A B C D E F G
>
> Right now, I'm using this code:
>
> attach(data)
> data<-data.frame(ID1,ID2,data[,sort(colnames(data)[3:9])])
> detach(data)
>
> but that's not very elegant. Ideally I could specify which columns to sort 
> and which to leave "as is" (but my attempts to do so have failed).
>
> Thank you,
>
> Mark
>

How about:
> df <- data.frame(z=1:2,a=3:4,y=5:6)
> df
   z a y
1 1 3 5
2 2 4 6
> sortdf <- df[,sort(names(df))]
> sortdf
   a y z
1 3 5 1
2 4 6 2

David Scott

_________________________________________________________________
David Scott	Department of Statistics, Tamaki Campus
 		The University of Auckland, PB 92019
 		Auckland 1142,    NEW ZEALAND
Phone: +64 9 373 7599 ext 86830		Fax: +64 9 373 7000
Email:	d.scott at auckland.ac.nz

Graduate Officer, Department of Statistics
Director of Consulting, Department of Statistics



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