Eu faria algo como: set.seed(1) x = runif(100) y = runif(100, 1e5, 1e6) z = c(x, y) qs = quantile(z) lbls = prettyNum(qs) lbls = paste("(", lbls[-length(lbls)], ",", lbls[-1], "]", sep='') w = cut(z, qs, labels=lbls) b