[R] Is there a function to test if all the elements in a vector are unique

[Peng Yu]

On Tue, Dec 1, 2009 at 8:24 PM, Rolf Turner <r.turner at auckland.ac.nz> wrote:
>
> On 2/12/2009, at 3:09 PM, Peng Yu wrote:
>
>        <SNIP>
>
>> Here is my sessionInfo().
>
>        [Snotty comment deleted.]
>
>>> sessionInfo()
>>
>> R version 2.7.1 (2008-06-23)
>
>        <SNIP>
>
>        If you're going to use a version which is that antiquated
>        then you can expect a great many things not to work.
>
>        Version 2.10.1 is about to be released, for crying out loud!

Are are package installations backward compatible? Will R code that
works in order installations work in the new installations?