[R] repeat matrix rows as a whole

[Petr PIKAL]

Hi

what about

 rbind(a,a)
     [,1] [,2] [,3] [,4]
[1,]    1    2    3    4
[2,]    5    6    7    8
[3,]    1    2    3    4
[4,]    5    6    7    8

Regards
Petr


> 
> > a <- matrix(1:8, 2, 4, byrow=TRUE)
> > a
>      [,1] [,2] [,3] [,4]
> [1,]    1    2    3    4
> [2,]    5    6    7    8
> > a[c(1,2,1,2),]
>      [,1] [,2] [,3] [,4]
> [1,]    1    2    3    4
> [2,]    5    6    7    8
> [3,]    1    2    3    4
> [4,]    5    6    7    8
> >
> 
> On Wed, Apr 25, 2012 at 8:32 PM, Rebecca <rebecca0420 at yahoo.cn> wrote:
> 
> > Hi,
> > If I have a matrix like
> > 1  2  3  4
> > 5  6  7  8,
> > how can I repeat two rows as whole, to be like
> > 1  2  3  4
> > 5  6  7  8
> > 1  2  3  4
> > 5  6  7  8?
> >
> > Since I have more two rows in a matrix and I need to repeat many 
times, I
> > wonder whether there is a convenient command to do so.
> >
> > Thanks!
> >        [[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<http://www.r-project.org/
> posting-guide.html>
> > and provide commented, minimal, self-contained, reproducible code.
> >
> >
> 
>    [[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.