[R] Picking out certain elements in an matrix

[Rolf Turner]

On 16/12/12 18:38, Tjun Kiat Teo wrote:
> Suppose I have  a matrix of data
>
> A
>
> 1  2 3
> 4  5 6
> 7  8 9
>
>
> And I have a vector of indexes 2,1,3
>
> For  row 1 of matrix A I want the 2nd element  2
> For  row 2 of matrix A I want the 1st element  4
> For  row 3 of matrix A I want the 3rd element 9.
>
> Is there a quick way to do it ?
A[cbind(1:3,c(2,1,3))]

     cheers,

         Rolf Turner