From: Tobias Verbeke <tobias.verbeke_at_telenet.be>

Date: Wed, 09 Apr 2008 22:11:45 +0200

*> x y z
*

*> b 3 8 8
*

*> c 4 7 7
*

*> h 9 2 4
*

*> e 6 5 1
*

*> f 7 4 2
*

*> a 2 9 9
*

> g 8 3 3

> d 5 6 6

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 Wed 09 Apr 2008 - 20:13:40 GMT

Date: Wed, 09 Apr 2008 22:11:45 +0200

Grant Gillis wrote:

> Hello,

*>
**> I have what I suspect might be an easy problem but I am new to R and
**> stumped. I have a data set that looks something like this
**>
**> b<-c(2,3,4,5,6,7,8,9)
**> x<-c(2,3,4,5,6,7,8,9)
**> y<-c(9,8,7,6,5,4,3,2)
**> z<-c(9,8,7,6,1,2,3,4)
**> data<-cbind(x,y,z)
**> row.names(data)<-c('a','b','c','d','e','f','g','h')
**>
**> which gives:
**>
**> x y z
**> a 2 9 9
**> b 3 8 8
**> c 4 7 7
**> d 5 6 6
**> e 6 5 1
**> f 7 4 2
**> g 8 3 3
**> h 9 2 4
**>
**> I would like to randomize data within columns. The closest I have been able
**> to come permutes data within the columns but keeps rows together along with
**> row names(example below). For some context, eventually I would like use
**> this to generate many data sets and perform calculations on these random
**> data sets (I think I know how to do this but we'll see). So ideally I would
**> like row names to remain the same (in order a through h) and column data to
**> randomize within columns but independently of the other columns. Just
**> shuffle the data deck I guess
**>
**>
*

>> data[permute(1:length(data[,1])),]

> g 8 3 3

> d 5 6 6

I changed 'data' to 'mymat' as 'data' is a function in R (see ?data) and added the row names after permuting:

someMatrix <- cbind(x, y, z)

permutedMat <- apply(someMatrix, 2, sample)
row.names(permutedMat)<-c('a','b','c','d','e','f','g','h')
permutedMat

**HTH,
**

Tobias

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 Wed 09 Apr 2008 - 20:13:40 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 Wed 09 Apr 2008 - 20:30:40 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.
*