→unique 関数を使う。 SQL でいう DISTINCT のようなものは無いのか?、と思って探したらやっぱり存在した。 > n<-c("Y","K","F","Y","K","Y","K","Y","K","Y","K","F","F") > unique(n) [1] "Y" "K" "F" > d<-c(8,11,23,21,1,8,21,6,4,23,1,4,9) > sort(unique(d)) [1] 1 4 6 8 9 11 21 23 一方、繰り返し出現した際の TRUE/FALSE が欲しい場合は、duplicated 関数を使う > n<-c("Y","K","F","Y","K","Y","K","Y","K","Y","K","F","F") > duplicated(n) [1] FALSE FALSE FALSE TRUE TRUE TRUE TRUE T