set.seed(314159265) height <- rnorm(30, 170, 7) factor(cut(height, breaks = quantile(height, c(0, 0.25, 0.50, 0.75, 1)), include.lowest = TRUE))
[1] (175,181] (167,172] (167,172] (167,172] (167,172] [158,167] (175,181] (175,181] (167,172] [10] (172,175] (167,172] (172,175] (175,181] [158,167] [158,167] (175,181] [158,167] (175,181] [19] (172,175] (172,175] (172,175] (175,181] [158,167] [158,167] [158,167] [158,167] (175,181] [28] (172,175] (167,172] (172,175] Levels: [158,167] (167,172] (172,175] (175,181]
たまに使いそう。