Your specification is a unclear (to me anyway): What do you want to return if the intersection is empty? What if intersect(ja[[i]], ja[[i+1]]) is empty for all i? What if length(intersect( ja[[i]], ja[[i+1]] )) ==0 but intersect(ja[[i]],ja[[i+2]]) is nonempty? Your example isn't -- you did not specify what the return should be on your list.
Note also that your example test is wrong: the length of the intersection must =0 not the intersection. -- Bert On Sat, Nov 9, 2013 at 12:45 PM, Hermann Norpois <hnorp...@gmail.com> wrote: > Hello, > > I have a list called ja and I wish to unify list objects if there is some > overlap. > For instance something like > > if (length (intersect (ja[[1]], ja[[2]]) !=0) { union (ja[[1]], ja[[2]] } > > but of course it should work cumulatively (for larger data sets). > > Could you please give me a hint. > > Thanks > Hermann > >> ja > $A > [1] "A" "B" "F" "G" "H" > > $B > [1] "B" "F" "I" > > $C > [1] "C" "F" "I" "K" > > $D > [1] "D" "L" "M" "N" > > $L > [1] "L" "O" "P" > > > dput (ja) > structure(list(A = c("A", "B", "F", "G", "H"), B = c("B", "F", > "I"), C = c("C", "F", "I", "K"), D = c("D", "L", "M", "N"), L = c("L", > "O", "P")), .Names = c("A", "B", "C", "D", "L")) > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics (650) 467-7374 ______________________________________________ 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.