[R] Picking out certain elements in an matrix
David Winsemius
dwinsemius at comcast.net
Sun Dec 16 07:03:22 CET 2012
On Dec 15, 2012, at 9:38 PM, 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.
A[ cbind( 1:3, c(2,1,3) ) ]
--
David Winsemius
Alameda, CA, USA
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