[R] Sorting a matrix by a column

[Dimitris Rizopoulos]

probably you need order(), e.g.,

data[order(data[, 2]), ]


I hope it helps.

Best,
Dimitris


John Sorkin wrote:
> R 2.6
> Windows XP
> 
> I have a 100x4 matirx
> 
> data<-matrix(nrow=100,ncol=4)
> 
> I would like to sort the entire matrix by column two, i.e. data[,2]
> I looked at the help page for sort() but can not determine how I can use it to sort a matrix on one of the matrix's columns.
> 
> Thanks,
> John 
> 
> John David Sorkin M.D., Ph.D.
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology
> Baltimore VA Medical Center
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