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mutate`:=`和mutate之间的tidyeval差异`=`

dplyr function r

stackinator Brenton Wiernik · 技术社区 · 7 年前

尽管这两个代码块使用不同的等号,其中一个是 := 另一个是 = . 哪个是正确的,为什么?我认为蒂迪瓦尔是必需的当使用dplyr函数时,但很奇怪 =

1.

library(tidyverse)
set.seed(1)
graph.data <- tibble(cal.date = as.Date(40100:40129, origin = "1899-12-30"), 
                     random_num = rnorm(30, 8, 5))

child_function <- function(df, variable, hor.line = 6) {  
  variable <- enquo(variable)
  df <- mutate(df, mutation := 2 * !! variable, horizontal.line := hor.line)
  df
}

child_function(graph.data, variable = random_num, hor.line=8)

2.

library(tidyverse)
set.seed(1)
graph.data <- tibble(cal.date = as.Date(40100:40129, origin = "1899-12-30"), 
                     random_num = rnorm(30, 8, 5))

child_function <- function(df, variable, hor.line = 6) {  
  variable <- enquo(variable)
  df <- mutate(df, mutation = 2 * !! variable, horizontal.line = hor.line)
  df
}

child_function(graph.data, variable = random_num, hor.line=8)

3 回复 | 直到 7 年前

arg0naut91 7 年前

没有义务将 := 那样的话。

child_function <- function(df, variable, hor.line = 6, mt_name = "mutation") {  

  variable <- enquo(variable)

  df <- mutate(df, !! mt_name := 2 * !! variable, horizontal.line = hor.line)

}