Hello, having a data frame like test with pairs of characters I would like to create chains. For instance from the pairs A/B and B/I you get the vector A B I. It is like jumping from one pair to the next related pair. So for my example test you should get: A B F G H I C F I K D L M N O P
> test V1 V2 1 A B 2 A F 3 A G 4 A H 5 B F 6 B I 7 C F 8 C I 9 C K 10 D L 11 D M 12 D N 13 L O 14 L P Thanks Hermann > dput (test) structure(list(V1 = c("A", "A", "A", "A", "B", "B", "C", "C", "C", "D", "D", "D", "L", "L"), V2 = c("B", "F", "G", "H", "F", "I", "F", "I", "K", "L", "M", "N", "O", "P")), .Names = c("V1", "V2"), row.names = c(NA, -14L), class = "data.frame") > [[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.