我有学校数据显示每个种族组中学生的百分比（黑人学生/总学生）。
我的示例数据如下：
School Race perc_race
1 EnrollBlack 3
2 EnrollBlack 67
3 EnrollWhite 4
4 EnrollWhite 8
5 EnrollHis 55
6 EnrollHis 88
7 EnrollAsian 43
8 EnrollAsian 34
我正在尝试为每个种族创建一个虚拟变量，以显示一所学校所处的位置。例如，如果一所学校有20％的黑人学生，则黑人的值为1，因为该学校属于第一等项。如果学校有67％的黑色，则它们将落入第三等分线，并且在黑色栏中会显示“ 3”。
School Race Percent_race black white hisp asian
1 EnrollBlack 3 1
2 EnrollBlack 67 3
3 EnrollWhite 4 1
4 EnrollWhite 8 1
5 EnrollHis 55 2
6 EnrollHis 88 3
7 EnrollAsian 43 2
8 EnrollAsian 3 4 2
我可以为数据集中的每个比赛重复此代码块，但是可以通过相应地替换比赛（即“ EnrollWhite”，“ EnrollHis” ...]
mutate(black = case_when(race=='EnrollBlack' & perc_race>66.66 ~"3",
race=='EnrollBlack' & perc_race>33.33 ~"2",
race=='EnrollBlack' & perc_race<=33.33 ~"1"))
而不是复制粘贴5次，我试图提供一个用户定义的函数，例如this。
def_tercile <- function(x,y){
mutate(y = case_when(race=='x' & perc_race>66.66 ~"3",
race=='x' & perc_race>33.33 ~"2",
race=='x' & perc_race<=33.33 ~"1"))
}
Where data％>％def_tercile（EnrollWhite，White）将返回一个新列，该列定义了学校所属的“白色”工具。
我不确定dplyr是否可以以这种方式在函数中使用（运行函数时，它会不断抛出错误）。关于如何处理此问题有任何想法吗？
library("tidyverse")
df <- read_table2("School Race perc_race
1 EnrollBlack 3
2 EnrollBlack 67
3 EnrollWhite 4
4 EnrollWhite 8
5 EnrollHis 55
6 EnrollHis 88
7 EnrollAsian 43
8 EnrollAsian 34")
要获得伸缩性，我们可以将其除以33.33并加1。
df %>%
group_by(Race) %>%
mutate(
tercile = 1 + perc_race %/% (100/3)
)
#> # A tibble: 8 x 4
#> # Groups: Race [4]
#> School Race perc_race tercile
#> <dbl> <chr> <dbl> <dbl>
#> 1 1 EnrollBlack 3 1
#> 2 2 EnrollBlack 67 3
#> 3 3 EnrollWhite 4 1
#> 4 4 EnrollWhite 8 1
#> 5 5 EnrollHis 55 2
#> 6 6 EnrollHis 88 3
#> 7 7 EnrollAsian 43 2
#> 8 8 EnrollAsian 34 2
然后我们可以使用pivot_wider给他们自己的列。
df %>%
group_by(Race) %>%
mutate(
tercile = 1 + perc_race %/% (100/3),
simple_race = Race %>% str_replace("Enroll", "") %>% str_to_lower()
) %>%
pivot_wider(names_from = simple_race, values_from = tercile)
#> # A tibble: 8 x 7
#> # Groups: Race [4]
#> School Race perc_race black white his asian
#> <dbl> <chr> <dbl> <dbl> <dbl> <dbl> <dbl>
#> 1 1 EnrollBlack 3 1 NA NA NA
#> 2 2 EnrollBlack 67 3 NA NA NA
#> 3 3 EnrollWhite 4 NA 1 NA NA
#> 4 4 EnrollWhite 8 NA 1 NA NA
#> 5 5 EnrollHis 55 NA NA 2 NA
#> 6 6 EnrollHis 88 NA NA 3 NA
#> 7 7 EnrollAsian 43 NA NA NA 2
#> 8 8 EnrollAsian 34 NA NA NA 2
要回答有关dplyr函数的问题，可以这样编写要定义的函数。对于将race_name作为列名处理的函数，我们需要使用!!和:=语法。
def_tercile <- function(data, race_value, race_name) {
mutate(data,
!!race_name := case_when(
Race == race_value & perc_race > 66.66 ~ "3",
Race == race_value & perc_race > 33.33 ~"2",
Race == race_value & perc_race <= 33.33 ~"1")
)
}
df %>%
def_tercile("EnrollBlack", "black") %>%
def_tercile("EnrollWhite", "white") %>%
def_tercile("EnrollHis", "his") %>%
def_tercile("EnrollAsian", "asian")
#> # A tibble: 8 x 7
#> School Race perc_race black white his asian
#> <dbl> <chr> <dbl> <chr> <chr> <chr> <chr>
#> 1 1 EnrollBlack 3 1 NA NA NA
#> 2 2 EnrollBlack 67 3 NA NA NA
#> 3 3 EnrollWhite 4 NA 1 NA NA
#> 4 4 EnrollWhite 8 NA 1 NA NA
#> 5 5 EnrollHis 55 NA NA 2 NA
#> 6 6 EnrollHis 88 NA NA 3 NA
#> 7 7 EnrollAsian 43 NA NA NA 2
#> 8 8 EnrollAsian 34 NA NA NA 2