[R] extract rows of a matrix

[Greg Snow]

> newmat <- oldmat[ c(rep(FALSE,19),TRUE), ]

Or

> newmat <- oldmat[ seq(20, nrow(oldmat), 20), ]


-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of li li
> Sent: Tuesday, October 12, 2010 2:00 PM
> To: r-help
> Subject: [R] extract rows of a matrix
> 
> Hi all,
>   I want to extract every 20th row of a big matrix, say 10000 by 1000.
> What is the simper way to do this?
>    Thank you very much!
>             Hannah
> 
> 	[[alternative HTML version deleted]]
> 
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