[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)],sep=))) a1 a2 a3 a4 b1 b2 b3 c1 c2d ab ac ad ae bc bd be cd ce de -- 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 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
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 lwald...@uhnres.utoronto.ca wrote: 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)],sep=))) a1 a2 a3 a4 b1 b2 b3 c1 c2d ab ac ad ae bc bd be cd ce de -- 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 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
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 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
