[R] permutates and/or samples a matrix

Gabor Csardi csardi at rmki.kfki.hu
Thu Jan 31 14:48:06 CET 2008


I mean

On Thu, Jan 31, 2008 at 02:32:20PM +0100, Gabor Csardi wrote:
> What exactly is the question? Selecting/permuting rows?
> 
> M[sample(length=nrow(M), count), ]

M[sample(seq(length=nrow(M)), count), ]

> Selecting/permuting columns?
> 
> M[ , sample(length=ncol(M), count) ]

M[ , sample(seq(length=ncol(M)), count) ]

G.

> Permuting elements?
> 
> structure(sample(M), dim=dim(M))
> 
> Selecting elements?
> 
> sample(M, count)
> 
> Gabor
> 
> On Thu, Jan 31, 2008 at 09:10:11PM +0800, Ng Stanley wrote:
> > Hi,
> > 
> > sample(x) only permutates and/or samples from a vector, which I can't use
> > for a matrix. Please help.
> > 
> > Thanks
> > Stanley
> > 
> > 	[[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.
> 
> -- 
> Csardi Gabor <csardi at rmki.kfki.hu>    UNIL DGM
> 
> ______________________________________________
> 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.

-- 
Csardi Gabor <csardi at rmki.kfki.hu>    UNIL DGM



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