Hello everybody,
is there any way to treat NA's as zero when they are summed up with numbers, but to treat them as NA's when summed up only with NA's. Specifically want that: 5+NA=5, but NA+NA=NA (and not zero). Any ideas? Best, S.B. [[alternative HTML version deleted]] ______________________________________________ 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.