Hello Wendy,

The simplest solution that comes to mind is to just use cbind.

For instance:

> x <- matrix(1:4, nrow=2)

> x
     [,1] [,2]
[1,]    1    3

[2,]    2    4

> cbind(x,x,x,c(2,5)) # repeat x here as many times as needed

     [,1] [,2] [,3] [,4] [,5] [,6] [,7]
[1,]    1    3    1    3    1    3    2

[2,]    2    4    2    4    2    4    5

I hope that helps.  Admittedly, this is not the best solution if you need to
replicate a matrix many times.

Best,

Joshua

On Sat, Feb 20, 2010 at 6:58 PM, wendy <wendy.qiao@utoronto.ca> wrote:

>
> Hi all,
>
> I have a matrix, for example
>     [,1] [,2]
> [1,]  1    3
> [2,]  4    6
>
> I want to replicate the matrix twice and add an extra column at the end,
> which is
>     [,1] [,2] [,3] [,4] [,5] [,6] [,7]
> [1,]  1    3     1    3     1    3    2
> [2,]  4    6     4    6     4    6    5
>
> I found 'rep' only works for vector. Does anyone know how to replicate a
> matrix, and append the matrix?
>
> Thank you in advance,
> Wendy
>
>
> --
> View this message in context:
> http://n4.nabble.com/replicate-matrix-tp1563337p1563337.html
> Sent from the R help mailing list archive at Nabble.com.
>
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Joshua Wiley
Senior in Psychology
University of California, Riverside
http://www.joshuawiley.com/

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