[R] replicate matrix

[amarov]

You can try something like:

mtx <- matrix(1:4, ncol = 2)

mtx.rep <- t(apply(mtx, 1, rep, r))

mtx.rep <- cbind(mrx.rep, new.column)

where r is your desired number of replications .

Hope it helps,

Boyko

Joshua Wiley-2 wrote:
> 
> 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 at 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
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>>
>> ______________________________________________
>> 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.
>>
> 
> 
> 
> -- 
> Joshua Wiley
> Senior in Psychology
> University of California, Riverside
> http://www.joshuawiley.com/
> 
> 	[[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.
> 
> 

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