[R] How to refer to the last a few rows?

[Peng Yu]

On Thu, Nov 5, 2009 at 7:24 AM, jim holtman <jholtman at gmail.com> wrote:
> will this do:
>
>> x
>     [,1] [,2] [,3] [,4] [,5]
> [1,]    1    6   11   16   21
> [2,]    2    7   12   17   22
> [3,]    3    8   13   18   23
> [4,]    4    9   14   19   24
> [5,]    5   10   15   20   25
>> tail(x[,tail(seq(ncol(x),3))], 2)
>     [,1] [,2] [,3]
> [4,]   24   19   14
> [5,]   25   20   15
>>

I would avoid to type the variable name twice. Because this is very
inconvenient when the variable name is long.

a_loooooooooooooooooong_expression_or_variable[nrow(a_loooooooooooooooooong_expression_or_variable),]

BTW, you misunderstood my question. My question was whether is a
better way to get the last a few columns than 't(tail(t(x),2))'.