Doing ?factor I get: x a vector of data, usually taking a small number of distinct values. levels an optional vector of the values that x might have taken. The default is the set of values taken by x, sorted into increasing order.
So if I do: factor(letters[1:20],level=seq(1:20) [1] <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> [16] <NA> <NA> <NA> <NA> <NA> Levels: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 So why all of the NA? What happend to 'a'. 'b', etc.? I was expecting a=1, b=2, c=3 etc. I am missing something. Please help with my understanding. Keviin ______________________________________________ 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.
