Hi, ?vec1<- factor(1:5,levels=1:10) ?vec1 #[1] 1 2 3 4 5 #Levels: 1 2 3 4 5 6 7 8 9 10 vec2<-droplevels(vec1) ?levels(vec2) #[1] "1" "2" "3" "4" "5" ?vec2 #[1] 1 2 3 4 5 #Levels: 1 2 3 4 5 A.K. Hi all, I am having a bit of trouble using the levels() function. I have a factor with many elements, and when I use the function levels() to extract the list of unique elements, some of the elements returned are not actually in the factor. For example I would have this:
vector <- dataset$Benchmark class(vector)
[1] "factor"
length(vector)
[1] 35615
vector2 <- levels(vector) length(which(!(vector2 %in% vector)))
[1] 235 Does anyone know how this is possible? Many thanks! Borja