I am so sorry for the lack of clarity. I have a few subjects, every subject has done a number of trials and per trial there is a measurement per millisecond (represented in the variable tt), so every unique trial is represented in around 2500 rows.
An example of data would be: Subj | Trial | tt | v4 | v5 | ... | v17 1 1 1 .. 1 1 2 .. 1 1 3 .. 1 1 4 .. 1 1 5 .. 1 2 1 .. 1 2 2 .. 1 2 3 .. 1 3 1 .. 1 3 2 .. 1 3 3 .. 2 1 1 .. 2 1 2 .. 2 1 3 .. etc. In the above dataset, how can I single out the trial that > 4, and delete the last two rows (tt = 4&5). I hope this makes more sense. -- View this message in context: http://r.789695.n4.nabble.com/Select-the-last-rows-of-when-specific-conditions-are-met-tp4648133p4648157.html Sent from the R help mailing list archive at Nabble.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.