Hi Georg, This was an interesting challenge to me. Here's what I came up with. The first option meets your desired result, but could get messy with deeper nesting. The second is less code, but is not quite what you want and requires as.data.frame() to give a reasonable result for each list. Calling either option a "good solution" would be rather generous. I'm iinterested to see what other people do.
Josh ## Data list.1 <- list("I"=list("A"=c("a", "b", "c"), "B"=c("d", "e", "f")), "II"=list("A"=c("g", "h", "i"), "B"=c("j", "k", "l"))) list.2 <- list("I"=list("A"=c("A", "B", "C"), "B"=c("D", "E", "F")), "II"=list("A"=c("G", "H", "I"), "B"=c("J", "K", "L"))) ## Try 1 list.t1 <- list.1 for(i in length(list.1)) { for(j in length(list.1[[i]])) { list.t1[[c(i, j)]] <- c(list.1[[c(i, j)]], list.2[[c(i, j)]]) } } ## Try 2 list.t2 <- as.list(do.call("rbind", lapply(list(list.1, list.2), as.data.frame, stringsAsFactors = FALSE))) ## Results list.t1 list.t2 On Tue, Jan 11, 2011 at 7:44 AM, Georg Otto <g...@well.ox.ac.uk> wrote: > Dear R gurus, > > > first let me apologize for a question that might hve been answered > before. I was not able to find the solution yet. I want to concatenate > two lists of lists at their lowest level. > > Suppose I have two lists of lists: > > list.1 <- list("I"=list("A"=c("a", "b", "c"), "B"=c("d", "e", "f")), > > "II"=list("A"=c("g", "h", "i"), "B"=c("j", "k", "l"))) > > > list.2 <- list("I"=list("A"=c("A", "B", "C"), "B"=c("D", "E", "F")), > > "II"=list("A"=c("G", "H", "I"), "B"=c("J", "K", "L"))) > > > >> list.1 > $I > $I$A > [1] "a" "b" "c" > > $I$B > [1] "d" "e" "f" > > > $II > $II$A > [1] "g" "h" "i" > > $II$B > [1] "j" "k" "l" > > >> list.2 > $I > $I$A > [1] "A" "B" "C" > > $I$B > [1] "D" "E" "F" > > > $II > $II$A > [1] "G" "H" "I" > > $II$B > [1] "J" "K" "L" > > > Now I want to concatenate list elements of the lowest levels, so the > result looks like this: > > > $I > $I$A > [1] "a" "b" "c" "A" "B" "C" > > $I$B > [1] "d" "e" "f" "D" "E" "F" > > > $II > $II$A > [1] "g" "h" "i" "G" "H" "I" > > $II$B > [1] "j" "k" "l" "J" "K" "L" > > > Has anybody a good solution for that? > > Best, > > Georg > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/ ______________________________________________ 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.