r - 有没有办法在 tidyverse 生态系统中使用循环？

Question

我曾尝试通过 mutate 和 fct_recode 函数循环来重新编码这个问题，但没有成功。有没有办法通过 tidyverse 或任何其他方式解决它？抱歉冗长 - 我想尽可能清楚。

set.seed(2021)

df <- tibble(

  a1 = factor(ifelse(sign(rnorm(30))==-1, 0, 1), labels = c("", "Yes")),
  a2 = factor(ifelse(sign(rnorm(30))==-1, 0, 1), labels = c("", "Yes")),
  b1 = factor(ifelse(sign(rnorm(30))==-1, 0, 1), labels = c("", "Yes")),
  b2 = factor(ifelse(sign(rnorm(30))==-1, 0, 1), labels = c("", "Yes")),
  d1 = gl(2, 15, labels = c("Males", "Females")),
  d2 = factor(ifelse(sign(rnorm(30))==-1, 0, 1), labels = c("Python", "R"))
)

df %>% count(a1)

# Replace "" with No

myvars <- c("a1", "a2", "b1", "b2")


df %>% mutate(a1 = factor(if_else(a1 == "", "No",
                                  as.character(a1))),
              a2 = factor(if_else(a1 == "", "No",
                                as.character(a1))),
              b1= factor(if_else(b1== "", "No",
                                  as.character(b1))))

#---- Attempt one (forloop)

# Desire for all the variables

for (i in myvars){

  df <- df %>%
    mutate(i = factor(if_else(i == "", "No",
                              as.character(i))))
}

df %>% count(a1) # No replacement

Answer 1

tidyverse有自己的“循环”功能。
要为多列应用函数，您可以使用 across .

library(dplyr)

df <- df %>% mutate(across(all_of(myvars), 
               ~factor(if_else(. == "", "No", as.character(.)))))

df %>% count(a1)

#  a1        n
#  <fct> <int>
#1 No       12
#2 Yes      18