根据与特定列的比较在 R tidyverse 中创建大量列

Question

我在 R tidyverse 中有一个数据集，我想根据与 sp 列的比较创建 192 列，就像 mp_comp_1 列一样。如何对 tidyverse 中的 192 列执行此操作？

library(tidyverse)    

df <- data.frame(matrix(ncol = 4, nrow = 3))

df%>%
  mutate(sp = c(34.9, 34.3, 34.4)) %>%
  mutate(mp_1 = c(35, 32.1, 34.4)) %>%
  mutate(mp_2 = c(30, 38.1, 39.4)) %>%
  mutate(mp_192 = c(34.9, 34.3, 30.4)) %>%
  select(sp, mp_1, mp_2, mp_192) %>%
  mutate(mp_comp_1= if_else(mp_1>sp, "bigger",
                            if_else(mp_1<sp, "smaller", "equal")))

Answer 1

您可以使用

across

和

case_when

。

library(dplyr)

df |> 
  mutate(across(starts_with("mp_"),
                ~case_when(.x > sp ~ "bigger",
                           .x < sp ~ "smaller",
                           .x == sp ~ "equal"),
                .names = "{.col}_comp"))

    sp mp_1 mp_2 mp_192 mp_1_comp mp_2_comp mp_192_comp
1 34.9 35.0 30.0   34.9    bigger   smaller       equal
2 34.3 32.1 38.1   34.3   smaller    bigger       equal
3 34.4 34.4 39.4   30.4     equal    bigger     smaller

数据

df <- structure(list(sp = c(34.9, 34.3, 34.4), mp_1 = c(35, 32.1, 34.4
), mp_2 = c(30, 38.1, 39.4), mp_192 = c(34.9, 34.3, 30.4)), class = "data.frame", row.names = c(NA, 
-3L))