[R] How to select randomly from a matrix?

[Domenico Vistocco]

WXE83 wrote:
> Dear all,
>
> I got one problem here and hoping someone can help me on this. Say I have a
> 50 by 2 matrix and I don't know how to randomly select:
>   
data <- matrix(1:25, 50, 2)
> 1. a pair of observations from the last 10th of the 50 observation from the
> matrix.
>   
 data[sample(41:50, 1, replace=FALSE),]
> 2. how to select randomly an observation from the first 5 observations of
> the second column in the matrix?
>   
data[sample(1:5, 1, replace=FALSE),2]

Ciao,
domenico
> Thanks....hope to hear from someone soon
>