"技术：case_when使用方法

{r setup, include=FALSE} knitr::opts_chunk$set(eval = FALSE) {r} library(tidyverse)

{r} b = data_frame(a = 1:100) b %>% mutate(c = case_when( a < 11 ~ '老大', a < 21 ~ '老二', TRUE ~ '老幺' )) %>% .$c %>% table()

如果我们满足了条件