[R] how to find unique pairs of variables?

[Sarah Goslee]

Hi Bonnie,

?unique probably would have done the trick for you. But here's an
example:
> z <- data.frame(x = rep(1:5, each=2), y = rep(1:2, each=5))
> z
   x y
1  1 1
2  1 1
3  2 1
4  2 1
5  3 1
6  3 2
7  4 2
8  4 2
9  5 2
10 5 2
> unique(z)
  x y
1 1 1
3 2 1
5 3 1
6 3 2
7 4 2
9 5 2
> nrow(unique(z))
[1] 6

Sarah


On Thu, Sep 15, 2011 at 12:27 PM,  <bby2103 at columbia.edu> wrote:
> I have two variables, both numerical. I would like to find the unique values
> of the pairs, in other words, unique coordinates if I were to plot them.
>
> I also need to know how many pairs there are, but I guess I can use length()
> if I can somehow isolate the unique pairs first?
>
> Thanks a lot!
>
> Bonnie Yuan
>
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-- 
Sarah Goslee
http://www.functionaldiversity.org