Hello R-Helpers! I have a data-frame as below (dput in the end of mail) and need to select just the first sequence of occurrence of each "Group" in each "ID".
For example, for ID "1" I have two sequential occurrences of T2 and two sequential occurrences of T3: > test [test$ID == 1, ] ID Group Var 3 1 T2 2.94 4 1 T2 3.23 5 1 T2 1.40 6 1 T2 1.62 7 1 T2 2.43 8 1 T2 2.53 9 1 T2 2.25 10 1 T3 1.66 11 1 T3 2.86 12 1 T3 0.53 13 1 T3 1.66 14 1 T3 3.24 15 1 T3 1.34 16 1 T2 1.86 17 1 T2 3.03 18 1 T3 3.63 19 1 T3 2.78 20 1 T3 1.49 As output, I need just the first group of T2 and T3 for this ID, like: ID Group Var 3 1 T2 2.94 4 1 T2 3.23 5 1 T2 1.40 6 1 T2 1.62 7 1 T2 2.43 8 1 T2 2.53 9 1 T2 2.25 10 1 T3 1.66 11 1 T3 2.86 12 1 T3 0.53 13 1 T3 1.66 14 1 T3 3.24 15 1 T3 1.34 For others ID I have just one occurrence or sequence of occurrence of each Group. I tried to use a labeling variable, but cannot figure out do this without many many loops.. Thanks in advanced, Raoni dput (teste) structure(list(ID = structure(c(3L, 4L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("1", "2", "3", "4"), class = "factor"), Group = structure(c(1L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 1L, 2L, 2L, 2L), .Label = c("T2", "T3"), class = "factor"), Var = c(0.32, 1.59, 2.94, 3.23, 1.4, 1.62, 2.43, 2.53, 2.25, 1.66, 2.86, 0.53, 1.66, 3.24, 1.34, 1.86, 3.03, 3.63, 2.78, 1.49, 2, 2.39, 1.65, 2.05, 2.75, 2.23, 1.39, 2.66, 1.05, 2.52, 2.49, 2.97, 0.43, 1.36, 0.79, 1.71, 1.95, 2.73, 2.73, 2.39, 2.17, 2.34, 2.42, 1.75, 0.66, 1.64, 0.24, 2.11, 2.11, 1.18)), .Names = c("ID", "Group", "Var"), row.names = c(NA, 50L ), class = "data.frame") ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.