Thank you very much got something running now based on this. Joh
jim holtman wrote: > building on the previous responses, does this give you what you want: > >> x > A B > 1 1 1 > 2 2 NA > 3 NA NA > 4 NA 4 >> # determine where the NAs are >> row.na <- apply(x, 1, is.na) >> # now convert to list of columns with NAs >> apply(row.na, 2, function(a) paste(colnames(x)[a], collapse = ',')) > [1] "" "B" "A,B" "A" >> >> > > > On Mon, Jan 17, 2011 at 5:01 AM, Johannes Graumann > <johannes_graum...@web.de> wrote: >> Hi, >> >> What is an efficient way to take this DF >> >> data.frame(A=c(1,2,NA,NA),B=c(1,NA,NA,4)) >> >> and get >> c(NA,"TWO","BOTH","ONE") >> >> as the result, where NA corresponds to a row without "NA"s, TWO indicates >> NA in the second and ONE in the first column. >> >> Thanks for any pointers. >> >> Joh >> >> ______________________________________________ >> 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.