Hello,
consider the following data.frame: test <- data.frame(n = c(1,2,3,4,5), v = c(6,5,7,5,3), pattern = c(1,1,NA,1,NA)) > test n v pattern 1 1 6 1 2 2 5 1 3 3 7 NA 4 4 5 1 5 5 3 NA I tried to use apply and the adply function to set v to NA where pattern = 1 and v to v where pattern = 1 So basically the result should look like this: > test n v pattern 1 1 NA 1 2 2 NA 1 3 3 7 NA 4 4 NA 1 5 5 3 NA So far, I solved it by creating subsets and using merge but it turns out to be super slow. Is there a way to do that with the apply function? Any help/hint is appreciated Thanks -- View this message in context: http://r.789695.n4.nabble.com/Delete-rows-from-data-frame-matching-a-certain-criteria-tp4435414p4435414.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.