Hi, May be this helps: ddNew <- transform(dd_1, CLASS= gsub("NA-|-NA","",paste(Class_a, Class_b, sep="-"))) identical(ddNew, dd_2) #[1] TRUE A.K.
On Thursday, May 22, 2014 4:07 AM, Beatriz R. Gonzalez Dominguez <aguitatie...@hotmail.com> wrote: Dear R-users, I'd be very greatful if you could help me with the following as after a few tests I haven't still been able to get the right outcome. I've got this data: dd_1 <- data.frame(ID = c("1","2", "3", "4", "5"), Class_a = c("a",NA, "a", NA, NA), Class_b = c(NA, "b", "b", "b", "b")) And I'd like to produce a new column 'CLASS': dd_2 <- data.frame(ID = c("1","2", "3", "4", "5"), Class_a = c("a",NA, "a", NA, NA), Class_b = c(NA, "b", "b", "b", "b"), CLASS = c("a", "b", "a-b", "b", "b")) Thanks a lot! ______________________________________________ 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. ______________________________________________ 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.