Dear All, wonder if you could please assist with the following
df<-data.frame(ID=c(1,1,1,2,2,3,3,4,4,5,5),samples=c("A","B","C","A","C","A","D","C","B","A","C")) from this data frame the goal is to extract the value of 3 from the ID column based on the logic that the ID=3 in the data frame has NO row that would pair 3 with either "B", AND/OR "C" in the samples column... much appreciate your help... thanks, Andras ______________________________________________ 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.