[R] expand the inside of command with rep ?

[jim holtman]

try this:

> x <- 1:5
> x.list <- lapply(1:15, function(a) x)
> do.call(cbind, x.list)
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12]
[,13] [,14] [,15]
[1,]    1    1    1    1    1    1    1    1    1     1     1     1
 1     1     1
[2,]    2    2    2    2    2    2    2    2    2     2     2     2
 2     2     2
[3,]    3    3    3    3    3    3    3    3    3     3     3     3
 3     3     3
[4,]    4    4    4    4    4    4    4    4    4     4     4     4
 4     4     4
[5,]    5    5    5    5    5    5    5    5    5     5     5     5
 5     5     5
>


On Wed, Feb 10, 2010 at 3:27 PM, Xu Wang <xuwang762 at gmail.com> wrote:
>
> Hi,
>
> I would like to be able to repeat a string within a command. I think there
> is an easy way but I can not figure out how.
>
> Here is an example.
>
> x<-1:15
> I would like to turn this into the following matrix:
> xm<-cbind(x,x,x,x,x)
>
> But I would like to do so by having a command that repeats x within the
> cbind command. Does that make sense? I have tried various things mainly
> involving the commands "rep" and "paste" but cannot get it.
>
> cbind(rep('x',times=5))
>
> I am guessing that this is not good programming etiquette? Something seems
> off about it. But still, I would like to know how to do it.
>
> I do understand that I can use a for loop to easily accomplish the desired
> output but am looking for a solution similar to the above syntax.
>
> Thank you for any ideas,
>
> Xu Wang
> --
> View this message in context: http://n4.nabble.com/expand-the-inside-of-command-with-rep-tp1476420p1476420.html
> Sent from the R help mailing list archive at Nabble.com.
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?