Question

我正在尝试使用因子水平的“密码本”（格式化为命名列表的列表）将大量数字变量转换为因子变量。我可以使用mutate()和recode_factor()一件一件地做，但是我想使用mutate_at()一件一件地做。我该怎么办？

codebook <- list(
  vs = list(`0` = 'V-shaped',
            `1` = 'straight'),
  am = list(`0` = 'automatic',
            `1` = 'manual')
)

mtcars %>%
  mutate(vs = recode_factor(vs, levels = !!!(pluck(codebook, 'vs'))))

mtcars %>%
  mutate_at(vars(names(codebook)),
            funs(recode_factor(., levels = !!!(pluck(codebook, 'somehow_pass_column_name_here?')))))

Answer 1

一种选择是遍历“密码本”的<div class="items-container">

names

或使用library(tidyverse) names(codebook) %>% map(~ mtcars %>% transmute(!! .x := recode_factor(!! rlang::sym(.x), levels = !!!(pluck(codebook, .x))))) %>% bind_cols(mtcars %>% select(-one_of(names(codebook))), .)循环

for

Answer 2

您仍然可以对多个变量使用mutate，除非您的含义是一对一。我对mutate_at不太了解，所以也许有人知道该方法。

mtcars %>%
  mutate(vs = recode_factor(vs, levels = !!!(pluck(codebook, 'vs'))),
         am = recode_factor(am, levels = !!!(pluck(codebook, 'am'))))

    mpg cyl  disp  hp drat    wt  qsec       vs        am gear carb
1  21.0   6 160.0 110 3.90 2.620 16.46 V-shaped    manual    4    4
2  21.0   6 160.0 110 3.90 2.875 17.02 V-shaped    manual    4    4
3  22.8   4 108.0  93 3.85 2.320 18.61 straight    manual    4    1
4  21.4   6 258.0 110 3.08 3.215 19.44 straight automatic    3    1
5  18.7   8 360.0 175 3.15 3.440 17.02 V-shaped automatic    3    2
6  18.1   6 225.0 105 2.76 3.460 20.22 straight automatic    3    1
7  14.3   8 360.0 245 3.21 3.570 15.84 V-shaped automatic    3    4
8  24.4   4 146.7  62 3.69 3.190 20.00 straight automatic    4    2
9  22.8   4 140.8  95 3.92 3.150 22.90 straight automatic    4    2
10 19.2   6 167.6 123 3.92 3.440 18.30 straight automatic    4    4

如何使用dplyr将变量从数字转换为具有唯一级别的因子

2 个答案: