Hi Hermann, You may want to use ?which, to store the index as well (might be handy in debugging or some other purposes if zeros has some special meaning) :
test <- c(1, 1, 1 , 1 , 1, 1, 2, 1, 1, 1, 0, 2, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 2, 1, 1, 1, 1, 1, 1) length(which(test==0)) But be careful when using == 0. If you are sure that elements are all integers I prefer this length(which(test <1)). Or a safe tolerance value from .Machine, if you are dealing with double numbers. length(which(test < .Machine$double.xmin)) -m ______________________________________________ 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.