Matrix: Problem with the code

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

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:

     x<-c(23,67,2,87,9,63,8,2,35,6,91,41,22,3)
     p <- 5
     mat<- matrix(0, nrow=p, ncol=length(x))
     for(j in 1:length(x))
     {
         for(i in 1:p)
             mat[i,j]<-x[j]^i
     }

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.

Sarah

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
http://www.functionaldiversity.org