[R] Matrix: Problem with the code

Sarah Goslee sarah.goslee at gmail.com
Sat Jan 10 01:24:08 CET 2009

Well, mat doesn't have any dimensions / isn't a matrix, and we don't
know what p is supposed to be. But leaving aside those little details,
do you perhaps want something like this:

      p <- 5
      mat<- matrix(0, nrow=p, ncol=length(x))
      for(j in 1:length(x))
          for(i in 1:p)

Two notes: I didn't try it out, and if that's what you want rather
than a toy example
of a larger problem, there are more elegant ways to do it in R.


On Fri, Jan 9, 2009 at 6:42 PM, Bhargab Chattopadhyay
<bhargab_1 at yahoo.com> wrote:
> Hi,
> Can any one please explain why the following code doesn't work? Or can anyone suggest an alternative.
> Suppose
>       x<-c(23,67,2,87,9,63,8,2,35,6,91,41,22,3)
>        mat<-0;
>        for(j in 1:length(x))
>        {
>           for(i in 1:p)
>                mat[i,j]<-x[j]^i;
>        }
>    Actually I want to have a matrix with p columns such that each column will have the elements of  x^(column#).
> Thanks in advance.
> Bhargab

Sarah Goslee

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