r - 如何从 case_when() 返回多个值或一个小标题？

Question

我找不到返回多个值(列)或仅来自 case_when() 的小标题的方法.

input <- tibble(a = c(1, 2, 3))

input %>%
  mutate(
    case =
      case_when(
        a == 1 ~ tibble(x = "case1", y = "c1"),
        a == 2 ~ tibble(x = "case2", y = "c2"),
        a == 3 ~ tibble(x = "case3", y = "c3")
        )
    )

如何根据某些正则表达式条件设置多个参数？

Answer 1

我们可以返回一个 list列为 mutate期望常规列是 vector与 length与原始数据的行数相同

input %>%
  mutate(
  case =
    case_when(
      a == 1 ~ list(tibble(x = "case1", y = "c1")),
      a == 2 ~ list(tibble(x = "case2", y = "c2")),
     a == 3 ~ list(tibble(x = "case3", y = "c3"))
     )
 )

-输出

# A tibble: 3 x 2
#      a case            
#  <dbl> <list>          
#1     1 <tibble [1 × 2]>
#2     2 <tibble [1 × 2]>
#3     3 <tibble [1 × 2]>