From: jim holtman <jholtman_at_gmail.com>

Date: Mon, 16 Jun 2008 08:18:21 -0400

> m[,c(1,2)] <- m[,c(2,1)]

*> m
*

*> colnames(m)[c(1,2)] <- colnames(m)[c(2,1)]
*

*> m
*

*>
*

Date: Mon, 16 Jun 2008 08:18:21 -0400

What you are doing with the assignment

m[,c(1,2)] <- m[,c(2,1)]

is only changing the values in the matrix; it knows nothing about the names. If you want the names of the columns switched, then you have to do it:

> m <- cbind(x=1:3, y=2:4, z=3:5)

*> m
*

x y z

[1,] 1 2 3 [2,] 2 3 4 [3,] 3 4 5

> m[,c(1,2)] <- m[,c(2,1)]

x y z

[1,] 2 1 3 [2,] 3 2 4 [3,] 4 3 5

y x z

[1,] 2 1 3 [2,] 3 2 4 [3,] 4 3 5

On Mon, Jun 16, 2008 at 8:10 AM, Daren Tan <daren76_at_hotmail.com> wrote:

*>
*

> How can I swap the column names at the same time ?

*>
**>> m <- cbind(x=1:3, y=2:4, z=3:5)> m x y z[1,] 1 2 3[2,] 2 3 4[3,] 3 4 5
**>> m[,c(1,2)] <- m[,c(2,1)]> m x y z[1,] 2 1 3[2,] 3 2 4[3,] 4 3 5
**> _________________________________________________________________
**>
**>
**> [[alternative HTML version deleted]]
**>
**> ______________________________________________
**> 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.
**>
*

-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ 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.Received on Mon 16 Jun 2008 - 12:27:57 GMT

Archive maintained by Robert King, hosted by
the discipline of
statistics at the
University of Newcastle,
Australia.

Archive generated by hypermail 2.2.0, at Mon 16 Jun 2008 - 12:30:44 GMT.

*
Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help.
Please read the posting
guide before posting to the list.
*