[R] selecting ith rows of a matrix

[Dimitris Rizopoulos]

probably you want to use seq(), e.g.,

mat <- matrix(1:500, 100, 5)

mat[seq(1, nrow(mat), 2), ]
mat[seq(1, nrow(mat), 3), ]
mat[seq(1, nrow(mat), 4), ]


I hope it helps.

Best,
Dimitris


Umesh Srinivasan wrote:
> Hi all,
> 
> If  I have a huge matrix/ dataframe and I want to create a new matrix/
> dataframe with every second (or third, or fourth etc.) row of the original
> matrix, how can I do it? Any help much appreciated.
> 
> Thanks,
> Umesh
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

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