[R] A matrix calculation

[David Winsemius]

On Aug 23, 2009, at 2:37 PM, Bogaso wrote:

>
> I have suppose a matrix like that
>
>> mat <- matrix(1:21, 7)
>> mat
>     [,1] [,2] [,3]
> [1,]    1    8   15
> [2,]    2    9   16
> [3,]    3   10   17
> [4,]    4   11   18
> [5,]    5   12   19
> [6,]    6   13   20
> [7,]    7   14   21
>
>> From this matrix, I want to create a vector like tha :
>
> c(mat[7,], mat[6,], mat[5,], ....., mat[1,])
>
> Can anyone please guide me, how to do that?

  c( mat[7:1,] )

# [1]  7  6  5  4  3  2  1 14 13 12 11 10  9  8 21 20 19 18 17 16 15

-- 

David Winsemius, MD
Heritage Laboratories
West Hartford, CT