Finding (swapped) repetitions of numbers pairs across two columns

Yep. There are methods for:

methods(unique)

[1] unique.array           unique.data.frame      unique.default        
[4] unique.matrix          unique.numeric_version unique.POSIXlt   

and for the matrix and data.frame methods, unique rows will be returned by default. For array and matrix objects, you can change the MARGIN argument to a different value (eg. 2 for columns, etc.).

See ?unique for more information, notably the Details and Value sections.

Marc

I did not know that unique worked on entire rows!

That is great, thank you very much!

Emmanuel


On 27 December 2012 22:39, Marc Schwartz <marc_schwartz at me.com> wrote:

unique(t(apply(cbind(v1, v2), 1, sort)))