[R] FW: Select a random subset of rows out of matrix

[David Winsemius]

On Mar 16, 2009, at 10:34 AM, Haenlein.Michael wrote:

> Dear all,
>
> I have a large dataset (N=100,000 with 89 variables per subject).  
> This dataset is stored in a 100.000 x 89 matrix where each row  
> describes one individual and each column one variable.
>
> What is the easiest way of selecting a subset of let's say 1.000  
> individuals out of that whole matrix?


bigmatrix[ sample( 1:nrow(bigmatrix), 1000, replace=FALSE), ]

>
>
> Thanks,
>
> Michael
>
>
> Michael Haenlein
> Associate Professor of Marketing
> ESCP-EAP European School of Management
> Paris, France
>
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>
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David Winsemius, MD
Heritage Laboratories
West Hartford, CT