Re: [R] getting all pairwise combinations of elements in a character string

I like both of these solutions much better - thank you! -Levi -- Levi Waldron post-doctoral fellow Jurisica Lab, Ontario Cancer Institute Division of Signaling Biology IBM Life Sciences Discovery Centre TMDT 9-304D 101 College Street Toronto, Ontario M5G 1L7 _

Re: [R] getting all pairwise combinations of elements in a character string

> combn(letters[1:5], 2) [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [1,] "a" "a" "a" "a" "b" "b" "b" "c" "c" "d" [2,] "b" "c" "d" "e" "c" "d" "e" "d" "e" "e" > On Thu, Feb 12, 2009 at 12:20 PM, Levi Waldron wrote: > I'm able to do this as follows, but am wondering

[R] getting all pairwise combinations of elements in a character string

I'm able to do this as follows, but am wondering if anyone knows a simpler way which still avoids explicit loops? > (mystring <- letters[1:5]) [1] "a" "b" "c" "d" "e" > unlist(sapply(mystring[-length(mystring)], + function(x) paste(x,mystring[(grep(x,mystring)+1):length(mystring)]