[R] looping problem

[Uwe Ligges]

Roslina Zakaria wrote:
> Dear r-expert,
> I would like to generate 30 sets of random numbers from uniform distribution (0,1). Each set of random numbers should have 90 data.  Here is my code:
> rand.no <- function(n,itr)
> { for (i in 1:itr)
>   {rand.1 <- runif(n,0,1)
>   if (i ==1) rand.2 <- rand.1
>   else rand.2 <- cbind(rand.2,rand.1)
>   }
>   rand.2
> }
> Question: The code is okay is just that it give me 31 sets instead of 30 sets. 

Works for me as expected, but really, why don't you simply say:

rand.no <- function(n,itr){
     matrix(runif(n*itr, 0, 1), nrow=n, ncol=itr)
}

which does the same, just much quicker...

Uwe Ligges




> Can anybody any adjustment to my code.
> Your help is really appreciated.
> Thank you.
> 
> 
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