(1) > a <- c("a", "b") > str(a) chr [1:2] "a" "b" > b <- c(1,2) > str(b) num [1:2] 1 2 > c <- data.frame(a, b) > str(c) 'data.frame': 2 obs. of 2 variables: $ a: Factor w/ 2 levels "a","b": 1 2 $ b: num 1 2 > mode(c$a) [1] "numeric" > c2 <- data.frame(a, b, stringsAsFactors=FALSE) > str(c2) 'data.frame': 2 obs. of 2 variables: $ a: chr "a" "b" $ b: num 1 2 > mode(c2$a) [1] "character"
(2) > a <- c("a", "a", "b", "b", "c") > levels(as.factor(a)) [1] "a" "b" "c" > b <- a[1:3] > b [1] "a" "a" "b" > levels(as.factor(b)) [1] "a" "b" > a <- as.factor(a) > a [1] a a b b c Levels: a b c > a[1:3] [1] a a b Levels: a b c On Sat, Jan 22, 2011 at 9:16 AM, analys...@hotmail.com <analys...@hotmail.com> wrote: > (1) > >> a = c("a","b") >> mode(a) > [1] "character" >> b = c(1,2) >> mode(b) > [1] "numeric" >> c = data.frame(a,b) >> mode(c$a) > [1] "numeric" > > (2) > > >> a = c("a","a","b","b","c") >> levels(as.factor(a)) > [1] "a" "b" "c" >> levels(as.factor(a[1:3])) > [1] "a" "b" >> a = as.factor(a) >> levels(a) > [1] "a" "b" "c" >> levels(a[1:3]) > [1] "a" "b" "c" > > Any explanation would be helpful. Thanks. > -- Sarah Goslee http://www.functionaldiversity.org ______________________________________________ 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.