# [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:

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#).
>
>
> Bhargab
>
>
>

--
Sarah Goslee
http://www.functionaldiversity.org

```