It is not entirely clear what you are asking for. Can you provide a sample of the output that you want from the data. Here is the data split by Measure_id, but not sure what to do with it:
> split(x, x$Measure_id) $`1` Measure_id i j value rank 1 1 2 1 1.5 0.7500000 6 1 2 3 2.0 1.0000000 11 1 2 4 1.0 0.5000000 16 1 4 3 2.0 1.0000000 21 1 5 1 2.0 1.0000000 26 1 5 2 1.5 0.7500000 31 1 7 3 1.5 1.0000000 36 1 7 5 1.0 0.6666667 $`2` Measure_id i j value rank 2 2 2 1 2.0 1.00 7 2 2 3 1.5 0.75 12 2 2 4 2.0 1.00 17 2 4 3 0.5 1.00 22 2 5 1 1.5 0.60 27 2 5 2 2.5 1.00 32 2 7 3 1.0 0.50 37 2 7 5 2.0 1.00 $`3` Measure_id i j value rank 3 3 2 1 1 1 8 3 2 3 0 0 13 3 2 4 0 0 18 3 4 3 1 1 23 3 5 1 0 NaN 28 3 5 2 0 NaN 33 3 7 3 0 NaN 38 3 7 5 0 NaN $`4` Measure_id i j value rank 4 4 2 1 0 0 9 4 2 3 0 0 14 4 2 4 1 1 19 4 4 3 0 NaN 24 4 5 1 0 0 29 4 5 2 1 1 34 4 7 3 0 NaN 39 4 7 5 0 NaN $`5` Measure_id i j value rank 5 5 2 1 2 1.0 10 5 2 3 1 0.5 15 5 2 4 2 1.0 20 5 4 3 2 1.0 25 5 5 1 1 0.5 30 5 5 2 2 1.0 35 5 7 3 1 1.0 40 5 7 5 1 1.0 > Jim Holtman Data Munger Guru What is the problem that you are trying to solve? Tell me what you want to do, not how you want to do it. On Mon, Nov 9, 2015 at 5:55 AM, Ragia Ibrahim <ragi...@hotmail.com> wrote: > Dear group, > > I have the following data freame > > dput(df_all_nodes) > > structure(list(Measure_id = c(1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, > 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, > 3, 4, 5, 1, 2, 3, 4, 5), i = c(2, 2, 2, 2, 2, 2, 2, 2, 2, 2, > 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 7, > 7, 7, 7, 7, 7, 7, 7, 7, 7), j = c(1, 1, 1, 1, 1, 3, 3, 3, 3, > 3, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, > 3, 3, 3, 3, 3, 5, 5, 5, 5, 5), value = c(1.5, 2, 1, 0, 2, 2, > 1.5, 0, 0, 1, 1, 2, 0, 1, 2, 2, 0.5, 1, 0, 2, 2, 1.5, 0, 0, 1, > 1.5, 2.5, 0, 1, 2, 1.5, 1, 0, 0, 1, 1, 2, 0, 0, 1), rank = c(0.75, > 1, 1, 0, 1, 1, 0.75, 0, 0, 0.5, 0.5, 1, 0, 1, 1, 1, 1, 1, NaN, > 1, 1, 0.6, NaN, 0, 0.5, 0.75, 1, NaN, 1, 1, 1, 0.5, NaN, NaN, > 1, 0.666666666666667, 1, NaN, NaN, 1)), .Names = c("Measure_id", > "i", "j", "value", "rank"), row.names = c(NA, 40L), class = "data.frame") > > > > I want to get maximum 3 rows in each group of Measure_id. e.g. for > measure_id 1 get the max ranks (select the max for each measure depending > on the rank column). > > how to do that > Best regards, > Ragia > > > > ______________________________________________ > 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. [[alternative HTML version deleted]] ______________________________________________ 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.