[R] listing of permutations

[Berton Gunter]

Erin:
You got 2 (so far) pre-packaged functions .Here's an obscenely inefficient
but short un-prepackaged way to do it:

k<-4
z<- do.call('expand.grid',as.data.frame(matrix(rep(1:k,k),nc=k)))
results<- z[apply(z,1,function(x)length(unique(x))==k),]

It is too inefficient to make public, though.

-- Bert Gunter
Genentech Non-Clinical Statistics
South San Francisco, CA
 
 

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Erin Hodgess
> Sent: Wednesday, August 02, 2006 9:57 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] listing of permutations
> 
> Dear R People:
> 
> Suppose I have the 4 numbers: 1,2,3,4.
> 
> I would like to create a listing of the permutations
> of 4 items taken 4 at a time.
> 
> Is there a built in function for that, please?
> 
> Thanks in advance!
> R 2-3-1 for Windows or Linux
> Sincerely,
> Erin Hodgess
> Associate Professor
> Department of Computer and Mathematical Sciences
> University of Houston - Downtown
> mailto: hodgess at gator.uhd.edu
> 
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